Index: wp-admin/update-core.php
===================================================================
--- wp-admin/update-core.php	(revision 12421)
+++ wp-admin/update-core.php	(working copy)
@@ -101,6 +101,7 @@
 	<?php screen_icon(); ?>
 	<h2><?php _e('Upgrade WordPress'); ?></h2>
 <?php
+	do_action('pre_core_upgrade_preamble');
 	if ( !isset($updates[0]->response) || 'latest' == $updates[0]->response ) {
 		echo '<h3>';
 		_e('You have the latest version of WordPress. You do not need to upgrade');