diff --git a/core/lib/Drupal/Core/Entity/DatabaseStorageControllerNG.php b/core/lib/Drupal/Core/Entity/DatabaseStorageControllerNG.php
index 6b6d5ff..98fdd69 100644
--- a/core/lib/Drupal/Core/Entity/DatabaseStorageControllerNG.php
+++ b/core/lib/Drupal/Core/Entity/DatabaseStorageControllerNG.php
@@ -77,13 +77,10 @@ public function __construct($entityType) {
    *   A new entity object.
    */
   public function create(array $values) {
-    $entity = new $this->entityClass(array(), $this->entityType);
+    // We have to determine the bundle first.
+    $bundle = $this->bundleKey ? $values[$this->bundleKey] : FALSE;
+    $entity = new $this->entityClass(array(), $this->entityType, $bundle);
 
-    // Make sure to set the bundle first.
-    if ($this->bundleKey && !empty($values[$this->bundleKey])) {
-      $entity->{$this->bundleKey} = $values[$this->bundleKey];
-      unset($values[$this->bundleKey]);
-    }
     // Set all other given values.
     foreach ($values as $name => $value) {
       $entity->$name = $value;
@@ -146,11 +143,14 @@ protected function attachLoad(&$queried_entities, $load_revision = FALSE) {
   protected function mapFromStorageRecords(array $records) {
 
     foreach ($records as $id => $record) {
+      $values = array();
       foreach ($record as $name => $value) {
-        $values[$name][LANGUAGE_DEFAULT][0]['value'] = $value;
+        // Avoid unnecessary array hierarchies to save memory.
+        $values[$name][LANGUAGE_DEFAULT] = $value;
       }
-      $entity = new $this->entityClass($values, $this->entityType);
-      $records[$id] = $entity;
+      $bundle = $this->bundleKey ? $record->{$this->bundleKey} : FALSE;
+      // Turn the record into an entity class.
+      $records[$id] = new $this->entityClass($values, $this->entityType, $bundle);
     }
     return $records;
   }
diff --git a/core/lib/Drupal/Core/Entity/EntityNG.php b/core/lib/Drupal/Core/Entity/EntityNG.php
index 5f0b044..4b9f10f 100644
--- a/core/lib/Drupal/Core/Entity/EntityNG.php
+++ b/core/lib/Drupal/Core/Entity/EntityNG.php
@@ -26,6 +26,13 @@
 class EntityNG extends Entity {
 
   /**
+   * Local cache holding the value of the bundle field.
+   *
+   * @var string
+   */
+  protected $bundle = FALSE;
+
+  /**
    * The plain data values of the contained fields.
    *
    * This always holds the original, unchanged values of the entity. The values
@@ -57,18 +64,23 @@ class EntityNG extends Entity {
   protected $bcEntity;
 
   /**
-   * Static cache for property definitions.
+   * Static cache for field definitions, keyed by entity type and bundle.
+   *
+   * @see self::getPropertyDefinitions()
    *
    * @var array
    */
-  protected $fieldDefinitions;
+  static $fieldDefinitions;
 
   /**
    * Overrides Entity::__construct().
    */
-  public function __construct(array $values, $entity_type) {
-    parent::__construct(array(), $entity_type);
-    $this->values = $values + $this->values;
+  public function __construct(array $values, $entity_type, $bundle = FALSE) {
+    $this->entityType = $entity_type;
+    $this->bundle = $bundle ? $bundle : $this->entityType;
+    foreach ($values as $key => $value) {
+      $this->values[$key] = $value;
+    }
     $this->init();
   }
 
@@ -76,6 +88,13 @@ public function __construct(array $values, $entity_type) {
    * Initialize the object. Invoked upon construction and wake up.
    */
   protected function init() {
+    if (!isset(static::$fieldDefinitions[$this->entityType][$this->bundle])) {
+      $definitions = entity_get_controller($this->entityType)->getFieldDefinitions(array(
+        'entity type' => $this->entityType,
+        'bundle' => $this->bundle,
+      ));
+      static::$fieldDefinitions[$this->entityType][$this->bundle] = $definitions;
+    }
     // We unset all defined properties, so magic getters apply.
     unset($this->langcode);
   }
@@ -88,10 +107,17 @@ public function __wakeup() {
   }
 
   /**
-   * Overrides Entity::id().
+   * Implements Drupal\Core\Entity\EntityInterface::id().
    */
   public function id() {
-    return $this->get('id')->value;
+    return $this->id->value;
+  }
+
+  /**
+   * Implements Drupal\Core\Entity\EntityInterface::bundle().
+   */
+  public function bundle() {
+    return $this->bundle;
   }
 
   /**
@@ -170,37 +196,15 @@ public function getIterator() {
    * Implements ComplexDataInterface::getPropertyDefinition().
    */
   public function getPropertyDefinition($name) {
-    // Try to read from static cache.
-    if (isset($this->fieldDefinitions)) {
-      return isset($this->fieldDefinitions[$name]) ? $this->fieldDefinitions[$name] : FALSE;
-    }
-
-    // First try getting property definitions which apply to all entities of
-    // this type. Then if this fails add in definitions of optional properties
-    // as well. That way we can use property definitions of base properties
-    // when determining the optional properties of an entity.
-    $definitions = entity_get_controller($this->entityType)->getFieldDefinitions(array());
-
-    if (isset($definitions[$name])) {
-      return $definitions[$name];
-    }
-    // Add in optional properties if any.
-    if ($definitions = $this->getPropertyDefinitions()) {
-      return isset($definitions[$name]) ? $definitions[$name] : FALSE;
-    }
+    $definitions = &static::$fieldDefinitions[$this->entityType][$this->bundle];
+    return isset($definitions[$name]) ? $definitions[$name] : FALSE;
   }
 
   /**
    * Implements ComplexDataInterface::getPropertyDefinitions().
    */
   public function getPropertyDefinitions() {
-    if (!isset($this->fieldDefinitions)) {
-      $this->fieldDefinitions = entity_get_controller($this->entityType)->getFieldDefinitions(array(
-        'entity type' => $this->entityType,
-        'bundle' => $this->bundle(),
-      ));
-    }
-    return $this->fieldDefinitions;
+    return static::$fieldDefinitions[$this->entityType][$this->bundle];
   }
 
   /**
@@ -366,7 +370,7 @@ public function &__get($name) {
       return $this->fields[$name][LANGUAGE_DEFAULT];
     }
     if ($this->getPropertyDefinition($name)) {
-      $return = $this->get($name);
+      $return = $this->getTranslatedField($name, LANGUAGE_DEFAULT);
       return $return;
     }
     // Allow the EntityBCDecorator to directly access the values and fields.
@@ -375,7 +379,7 @@ public function &__get($name) {
       return $this->$name;
     }
     // Else directly read/write plain values. That way, fields not yet converted
-    // to the entity field API can always be accessed as in compatibility mode.
+    // to the entity field API can always be directly accessed.
     if (!isset($this->values[$name])) {
       $this->values[$name] = NULL;
     }
@@ -395,10 +399,10 @@ public function __set($name, $value) {
       $this->fields[$name][LANGUAGE_DEFAULT]->setValue($value);
     }
     elseif ($this->getPropertyDefinition($name)) {
-      $this->get($name)->setValue($value);
+      $this->getTranslatedField($name, LANGUAGE_DEFAULT)->setValue($value);
     }
     // Else directly read/write plain values. That way, fields not yet converted
-    // to the entity field API can always be accessed as in compatibility mode.
+    // to the entity field API can always be directly accessed.
     else {
       $this->values[$name] = $value;
     }
diff --git a/core/lib/Drupal/Core/Entity/Field/Type/BooleanItem.php b/core/lib/Drupal/Core/Entity/Field/Type/BooleanItem.php
index af0652a..b6f9df6 100644
--- a/core/lib/Drupal/Core/Entity/Field/Type/BooleanItem.php
+++ b/core/lib/Drupal/Core/Entity/Field/Type/BooleanItem.php
@@ -21,7 +21,7 @@
 class BooleanItem extends FieldItemBase {
 
   /**
-   * Field definitions of the contained properties.
+   * Definitions of the contained properties.
    *
    * @see self::getPropertyDefinitions()
    *
diff --git a/core/lib/Drupal/Core/Entity/Field/Type/DateItem.php b/core/lib/Drupal/Core/Entity/Field/Type/DateItem.php
index 5201051..20d7437 100644
--- a/core/lib/Drupal/Core/Entity/Field/Type/DateItem.php
+++ b/core/lib/Drupal/Core/Entity/Field/Type/DateItem.php
@@ -21,7 +21,7 @@
 class DateItem extends FieldItemBase {
 
   /**
-   * Field definitions of the contained properties.
+   * Definitions of the contained properties.
    *
    * @see self::getPropertyDefinitions()
    *
diff --git a/core/lib/Drupal/Core/Entity/Field/Type/EntityReferenceItem.php b/core/lib/Drupal/Core/Entity/Field/Type/EntityReferenceItem.php
index 411aad1..b67a6d8 100644
--- a/core/lib/Drupal/Core/Entity/Field/Type/EntityReferenceItem.php
+++ b/core/lib/Drupal/Core/Entity/Field/Type/EntityReferenceItem.php
@@ -23,7 +23,7 @@
 class EntityReferenceItem extends FieldItemBase {
 
   /**
-   * Field definitions of the contained properties.
+   * Definitions of the contained properties.
    *
    * @see self::getPropertyDefinitions()
    *
diff --git a/core/lib/Drupal/Core/Entity/Field/Type/EntityWrapper.php b/core/lib/Drupal/Core/Entity/Field/Type/EntityWrapper.php
index 97449e7..6d743d0 100644
--- a/core/lib/Drupal/Core/Entity/Field/Type/EntityWrapper.php
+++ b/core/lib/Drupal/Core/Entity/Field/Type/EntityWrapper.php
@@ -70,7 +70,7 @@ class EntityWrapper extends TypedData implements IteratorAggregate, ComplexDataI
    * Implements TypedDataInterface::__construct().
    */
   public function __construct(array $definition) {
-    $this->definition = $definition + array('constraints' => array());
+    $this->definition = $definition;
     $this->entityType = isset($this->definition['constraints']['entity type']) ? $this->definition['constraints']['entity type'] : NULL;
   }
 
diff --git a/core/lib/Drupal/Core/Entity/Field/Type/IntegerItem.php b/core/lib/Drupal/Core/Entity/Field/Type/IntegerItem.php
index fc542f1..2ddc4d5 100644
--- a/core/lib/Drupal/Core/Entity/Field/Type/IntegerItem.php
+++ b/core/lib/Drupal/Core/Entity/Field/Type/IntegerItem.php
@@ -21,7 +21,7 @@
 class IntegerItem extends FieldItemBase {
 
   /**
-   * Field definitions of the contained properties.
+   * Definitions of the contained properties.
    *
    * @see self::getPropertyDefinitions()
    *
diff --git a/core/lib/Drupal/Core/Entity/Field/Type/LanguageItem.php b/core/lib/Drupal/Core/Entity/Field/Type/LanguageItem.php
index 646718b..1392119 100644
--- a/core/lib/Drupal/Core/Entity/Field/Type/LanguageItem.php
+++ b/core/lib/Drupal/Core/Entity/Field/Type/LanguageItem.php
@@ -22,9 +22,9 @@
 class LanguageItem extends FieldItemBase {
 
   /**
-   * Array of property definitions of contained properties.
+   * Definitions of the contained properties.
    *
-   * @see PropertyEntityReferenceItem::getPropertyDefinitions()
+   * @see self::getPropertyDefinitions()
    *
    * @var array
    */
diff --git a/core/lib/Drupal/Core/Entity/Field/Type/StringItem.php b/core/lib/Drupal/Core/Entity/Field/Type/StringItem.php
index 85fd6d6..bd22984 100644
--- a/core/lib/Drupal/Core/Entity/Field/Type/StringItem.php
+++ b/core/lib/Drupal/Core/Entity/Field/Type/StringItem.php
@@ -21,7 +21,7 @@
 class StringItem extends FieldItemBase {
 
   /**
-   * Field definitions of the contained properties.
+   * Definitions of the contained properties.
    *
    * @see self::getPropertyDefinitions()
    *
diff --git a/core/lib/Drupal/Core/TypedData/TypedDataFactory.php b/core/lib/Drupal/Core/TypedData/TypedDataFactory.php
index 3c87148..94b9dac 100644
--- a/core/lib/Drupal/Core/TypedData/TypedDataFactory.php
+++ b/core/lib/Drupal/Core/TypedData/TypedDataFactory.php
@@ -7,6 +7,7 @@
 
 namespace Drupal\Core\TypedData;
 
+use InvalidArgumentException;
 use Drupal\Component\Plugin\Factory\DefaultFactory;
 use Drupal\Component\Plugin\Exception\PluginException;
 
@@ -19,6 +20,13 @@
 class TypedDataFactory extends DefaultFactory {
 
   /**
+   * Static cache for definitions to speed things up.
+   *
+   * @var array
+   */
+  protected $definitions;
+
+  /**
    * Implements Drupal\Component\Plugin\Factory\FactoryInterface::createInstance().
    *
    * @param string $plugin_id
@@ -29,12 +37,18 @@ class TypedDataFactory extends DefaultFactory {
    * @return Drupal\Core\TypedData\TypedDataInterface
    */
   public function createInstance($plugin_id, array $configuration) {
-    $type_definition = $this->discovery->getDefinition($plugin_id);
 
-    // Allow per-data definition overrides of the used classes and generally
-    // default to the data type definition.
-    $key = empty($configuration['list']) ? 'class' : 'list class';
+    if (!isset($this->definitions)) {
+      $this->definitions = $this->discovery->getDefinitions();
+    }
+    if (!isset($this->definitions[$plugin_id])) {
+      throw new InvalidArgumentException(format_string('Invalid data type %plugin_id has been given.', array('%plugin_id' => $plugin_id)));
+    }
+
+    $type_definition = $this->definitions[$plugin_id];
 
+    // Allow per-data definition overrides of the used classes.
+    $key = empty($configuration['list']) ? 'class' : 'list class';
     if (isset($configuration[$key])) {
       $class = $configuration[$key];
     }
@@ -45,7 +59,6 @@ public function createInstance($plugin_id, array $configuration) {
     if (!isset($class)) {
       throw new PluginException(sprintf('The plugin (%s) did not specify an instance class.', $plugin_id));
     }
-
-    return new $class($configuration, $plugin_id, $this->discovery);
+    return new $class($configuration, $plugin_id);
   }
 }
diff --git a/core/lib/Drupal/Core/TypedData/TypedDataManager.php b/core/lib/Drupal/Core/TypedData/TypedDataManager.php
index a1522d8..d7f4ee1 100644
--- a/core/lib/Drupal/Core/TypedData/TypedDataManager.php
+++ b/core/lib/Drupal/Core/TypedData/TypedDataManager.php
@@ -94,7 +94,7 @@ public function createInstance($plugin_id, array $configuration) {
    * @see Drupal\Core\Entity\Field\EntityWrapper
    */
   function create(array $definition, $value = NULL, array $context = array()) {
-    $wrapper = $this->createInstance($definition['type'], $definition);
+    $wrapper = $this->factory->createInstance($definition['type'], $definition);
     if (isset($value)) {
       $wrapper->setValue($value);
     }
diff --git a/core/modules/comment/comment.module b/core/modules/comment/comment.module
index 5ba1050..53be66d 100644
--- a/core/modules/comment/comment.module
+++ b/core/modules/comment/comment.module
@@ -1666,7 +1666,7 @@ function template_preprocess_comment(&$variables) {
   $variables['author'] = theme('username', array('account' => $account));
   $variables['created'] = format_date($comment->created->value->getTimestamp());
   $variables['changed'] = format_date($comment->changed->value->getTimestamp());
-  $variables['new'] = !empty($comment->new->value) ? t('new') : '';
+  $variables['new'] = $comment->new->value ? t('new') : '';
   $variables['user_picture'] = theme_get_setting('toggle_comment_user_picture') ? theme('user_picture', array('account' => $account)) : '';
 
   if (config('user.settings')->get('signatures') && !empty($account->signature)) {
diff --git a/core/modules/comment/lib/Drupal/comment/CommentStorageController.php b/core/modules/comment/lib/Drupal/comment/CommentStorageController.php
index 488931e..24b32e0 100644
--- a/core/modules/comment/lib/Drupal/comment/CommentStorageController.php
+++ b/core/modules/comment/lib/Drupal/comment/CommentStorageController.php
@@ -56,14 +56,13 @@ protected function attachLoad(&$records, $load_revision = FALSE) {
    * Overrides Drupal\Core\Entity\DatabaseStorageControllerNG::create().
    */
   public function create(array $values) {
-    $comment = new $this->entityClass(array(), $this->entityType);
-
-    // Make sure the bundle is set first, so bundle specific values can be set.
-    if (!empty($values['nid'])) {
-      $comment->nid = $values['nid'];
-      $comment->node_type->value = 'comment_node_' . $comment->nid->entity->type;
-      unset($values['nid']);
+    // We have to determine the bundle first.
+    if (empty($values['node_type']) && !empty($values['nid'])) {
+      $node = node_load($values['nid']);
+      $values['node_type'] = 'comment_node_' . $node->type;
     }
+    $comment = new $this->entityClass(array(), $this->entityType, $values['node_type']);
+
     // Set all other given values.
     foreach ($values as $name => $value) {
       $comment->$name = $value;
diff --git a/core/modules/comment/lib/Drupal/comment/FieldNewValue.php b/core/modules/comment/lib/Drupal/comment/FieldNewValue.php
index eb22ba0..5afd132 100644
--- a/core/modules/comment/lib/Drupal/comment/FieldNewValue.php
+++ b/core/modules/comment/lib/Drupal/comment/FieldNewValue.php
@@ -68,13 +68,15 @@ public function setParent($parent) {
    * Implements TypedDataInterface::getValue().
    */
   public function getValue($langcode = NULL) {
-
-    if (!isset($this->parent)) {
-      throw new InvalidArgumentException('Computed properties require context for computation.');
+    if (!isset($this->value)) {
+      if (!isset($this->parent)) {
+        throw new InvalidArgumentException('Computed properties require context for computation.');
+      }
+      $field = $this->parent->getParent();
+      $entity = $field->getParent();
+      $this->value = node_mark($entity->nid->value, $entity->changed->value->getTimestamp());
     }
-    $field = $this->parent->getParent();
-    $entity = $field->getParent();
-    return node_mark($entity->nid->value, $entity->changed->value->getTimestamp());
+    return $this->value;
   }
 
   /**
diff --git a/core/modules/comment/lib/Drupal/comment/Plugin/Core/Entity/Comment.php b/core/modules/comment/lib/Drupal/comment/Plugin/Core/Entity/Comment.php
index cc13922..7530ed0 100644
--- a/core/modules/comment/lib/Drupal/comment/Plugin/Core/Entity/Comment.php
+++ b/core/modules/comment/lib/Drupal/comment/Plugin/Core/Entity/Comment.php
@@ -218,11 +218,4 @@ protected function init() {
   public function id() {
     return $this->get('cid')->value;
   }
-
-  /**
-   * Implements Drupal\Core\Entity\EntityInterface::bundle().
-   */
-  public function bundle() {
-    return $this->get('node_type')->value;
-  }
 }
diff --git a/core/modules/field/modules/text/lib/Drupal/text/Type/TextItem.php b/core/modules/field/modules/text/lib/Drupal/text/Type/TextItem.php
index 98b6bb6..e44fc1d 100644
--- a/core/modules/field/modules/text/lib/Drupal/text/Type/TextItem.php
+++ b/core/modules/field/modules/text/lib/Drupal/text/Type/TextItem.php
@@ -21,7 +21,7 @@
 class TextItem extends FieldItemBase {
 
   /**
-   * Field definitions of the contained properties.
+   * Definitions of the contained properties.
    *
    * @see self::getPropertyDefinitions()
    *
diff --git a/core/modules/field/modules/text/lib/Drupal/text/Type/TextSummaryItem.php b/core/modules/field/modules/text/lib/Drupal/text/Type/TextSummaryItem.php
index eb563ce..06f3be1 100644
--- a/core/modules/field/modules/text/lib/Drupal/text/Type/TextSummaryItem.php
+++ b/core/modules/field/modules/text/lib/Drupal/text/Type/TextSummaryItem.php
@@ -19,7 +19,7 @@
 class TextSummaryItem extends TextItem {
 
   /**
-   * Field definitions of the contained properties.
+   * Definitions of the contained properties.
    *
    * @see self::getPropertyDefinitions()
    *