Index: wp-includes/comment-template.php
===================================================================
--- wp-includes/comment-template.php	(revision 18627)
+++ wp-includes/comment-template.php	(working copy)
@@ -908,6 +908,8 @@
 	if ( !defined('COMMENTS_TEMPLATE') || !COMMENTS_TEMPLATE)
 		define('COMMENTS_TEMPLATE', true);
 
+	do_action( 'pre_comments_template', $post );
+
 	$include = apply_filters('comments_template', STYLESHEETPATH . $file );
 	if ( file_exists( $include ) )
 		require( $include );
@@ -915,6 +917,8 @@
 		require( TEMPLATEPATH .  $file );
 	else // Backward compat code will be removed in a future release
 		require( ABSPATH . WPINC . '/theme-compat/comments.php');
+
+	do_action( 'post_comments_template', $post );
 }
 
 /**