Index: wordpress/wp-includes/default-filters.php
===================================================================
--- wordpress/wp-includes/default-filters.php	(revision 21499)
+++ wordpress/wp-includes/default-filters.php	(working copy)
@@ -282,4 +282,7 @@
 add_action( 'admin_init', 'register_admin_color_schemes', 1);
 add_action( 'admin_color_scheme_picker', 'admin_color_scheme_picker' );
 
+// Quit early on HEAD requests
+add_action( 'head_request', 'handle_head_request' );
+
 unset($filter, $action);
Index: wordpress/wp-includes/functions.php
===================================================================
--- wordpress/wp-includes/functions.php	(revision 21499)
+++ wordpress/wp-includes/functions.php	(working copy)
@@ -3607,3 +3607,15 @@
 	return true;
 }
 
+/**
+ * Halt template load for HEAD requests. Performance bump by eliminating output
+ * 
+ * @since 3.5.0
+ */
+function handle_head_request() {	
+	if ( 'HEAD' === $_SERVER['REQUEST_METHOD'] && apply_filters( 'exit_on_http_head', true ) ) {
+		$function = create_function( '', "return '_scalar_wp_die_handler';" );
+		add_filter( 'wp_die_handler', $function );
+		wp_die();
+	}
+}
Index: wordpress/wp-includes/template-loader.php
===================================================================
--- wordpress/wp-includes/template-loader.php	(revision 21499)
+++ wordpress/wp-includes/template-loader.php	(working copy)
@@ -6,6 +6,13 @@
 if ( defined('WP_USE_THEMES') && WP_USE_THEMES )
 	do_action('template_redirect');
 
+/**
+ * Halt template load for HEAD requests. Performance bump by eliminating output
+ *
+ * @since 3.5.0
+ */
+do_action( 'head_request' );
+
 // Process feeds and trackbacks even if not using themes.
 if ( is_robots() ) :
 	do_action('do_robots');