Index: wp-includes/js/media-editor.js
===================================================================
--- wp-includes/js/media-editor.js	(revision 23230)
+++ wp-includes/js/media-editor.js	(working copy)
@@ -513,6 +513,11 @@
 
 			workflow.state('featured-image').on( 'select', wp.media.featuredImage.select );
 			workflow.setState( workflow.options.state );
+			
+			// Check if anyone has extended the object to manipulate the states and views before outputting on screen.
+			if ( this.extend && typeof(this.extend) === 'function' )
+				this.extend(workflow);
+				
 			return workflow;
 		},