Index: modules/events.inc
===================================================================
RCS file: /cvs/drupal-contrib/contributions/modules/rules/rules/modules/Attic/events.inc,v
retrieving revision 1.1.2.25
diff -u -p -r1.1.2.25 events.inc
--- modules/events.inc	9 Nov 2010 09:49:00 -0000	1.1.2.25
+++ modules/events.inc	21 Nov 2010 16:01:50 -0000
@@ -98,6 +98,10 @@ function rules_node_insert($node) {
   rules_invoke_event('node_insert', $node);
 }
 
+function rules_node_prepare($node) {
+  rules_invoke_event('node_prepare', $node);
+}
+
 function rules_node_delete($node) {
   rules_invoke_event('node_delete', $node);
 }
Index: modules/node.rules.inc
===================================================================
RCS file: /cvs/drupal-contrib/contributions/modules/rules/rules/modules/Attic/node.rules.inc,v
retrieving revision 1.1.4.21
diff -u -p -r1.1.4.21 node.rules.inc
--- modules/node.rules.inc	29 Oct 2010 14:59:59 -0000	1.1.4.21
+++ modules/node.rules.inc	21 Nov 2010 16:01:50 -0000
@@ -51,6 +51,12 @@ function rules_node_event_info() {
       ),
       'access callback' => 'rules_node_integration_access',
     ),
+    'node_prepare' => array(
+      'label' => t('Content is going to be edited'),
+      'group' => t('Node'),
+      'variables' => rules_events_node_variables(t('edited content'), TRUE),
+      'access callback' => 'rules_node_integration_access',
+    ),
     'node_delete' => array(
       'label' => t('After deleting content'),
       'group' => t('Node'),