Index: wp-admin/includes/update-core.php
===================================================================
--- wp-admin/includes/update-core.php	(revision 11699)
+++ wp-admin/includes/update-core.php	(working copy)
@@ -257,6 +257,8 @@
 
 	// Remove maintenance file, we're done.
 	$wp_filesystem->delete($maintenance_file);
+	
+	do_action('update_core_finished');
 }
 
 ?>