diff -rup feeds.b/plugins/FeedsNodeProcessor.inc feeds.a/plugins/FeedsNodeProcessor.inc
--- feeds.b/plugins/FeedsNodeProcessor.inc	2013-01-17 19:08:33.000000000 -0500
+++ feeds.a/plugins/FeedsNodeProcessor.inc	2013-01-18 18:45:07.078496638 -0500
@@ -54,7 +54,8 @@ class FeedsNodeProcessor extends FeedsPr
   protected function entityLoad(FeedsSource $source, $nid) {
     $node = parent::entityLoad($source, $nid);
 
-    if ($this->config['update_existing'] != FEEDS_UPDATE_EXISTING) {
+    if (($this->config['update_existing'] != FEEDS_UPDATE_EXISTING) &&
+        ($this->config['update_existing'] != FEEDS_SKIP_NEW)){
       $node->uid = $this->config['author'];
     }
 
@@ -68,7 +69,8 @@ class FeedsNodeProcessor extends FeedsPr
     }
 
     // Populate properties that are set by node_object_prepare().
-    if ($this->config['update_existing'] == FEEDS_UPDATE_EXISTING) {
+    if (($this->config['update_existing'] == FEEDS_UPDATE_EXISTING) ||
+        ($this->config['update_existing'] == FEEDS_SKIP_NEW)) {
       $node->log = 'Updated by FeedsNodeProcessor';
     }
     else {
Only in feeds.b/plugins: FeedsNodeProcessor.inc.orig
diff -rup feeds.b/plugins/FeedsProcessor.inc feeds.a/plugins/FeedsProcessor.inc
--- feeds.b/plugins/FeedsProcessor.inc	2013-01-17 19:08:33.000000000 -0500
+++ feeds.a/plugins/FeedsProcessor.inc	2013-01-18 18:48:56.078480637 -0500
@@ -9,6 +9,7 @@
 define('FEEDS_SKIP_EXISTING', 0);
 define('FEEDS_REPLACE_EXISTING', 1);
 define('FEEDS_UPDATE_EXISTING', 2);
+define('FEEDS_SKIP_NEW', 3);
 
 // Default limit for creating items on a page load, not respected by all
 // processors.
@@ -198,6 +199,12 @@ abstract class FeedsProcessor extends Fe
         continue;
       }
 
+      // Do not proceed if the item does not exist and we are set for update only
+      $skip_create = $this->config['update_existing'] == FEEDS_SKIP_NEW;
+      if (empty($entity_id) && $skip_create) {
+	continue;
+      }
+
       try {
 
         // Load an existing entity.
@@ -571,7 +578,8 @@ abstract class FeedsProcessor extends Fe
       '#options' => array(
         FEEDS_SKIP_EXISTING => t('Do not update existing @entities', $tokens),
         FEEDS_REPLACE_EXISTING => t('Replace existing @entities', $tokens),
         FEEDS_UPDATE_EXISTING => t('Update existing @entities', $tokens),
+        FEEDS_SKIP_NEW => t('Update existing nodes only (Do not create new nodes)', $tokens),
       ),
       '#default_value' => $this->config['update_existing'],
     );