Index: wp-includes/canonical.php
===================================================================
--- wp-includes/canonical.php	(revision 18621)
+++ wp-includes/canonical.php	(working copy)
@@ -265,6 +265,15 @@
 				$redirect['path'] = trailingslashit($redirect['path']) . $addl_path;
 			$redirect_url = $redirect['scheme'] . '://' . $redirect['host'] . $redirect['path'];
 		}
+
+		if ( 'wp-register.php' == basename( $redirect['path'] ) ) {
+			if ( is_multisite() )
+				$redirect_url = apply_filters( 'wp_signup_location', site_url('wp-signup.php') );
+			else
+				$redirect_url = site_url('wp-login.php?action=register');
+			wp_redirect( $redirect_url, 301 );
+			die();
+		}
 	}
 
 	// tack on any additional query vars
Index: wp-includes/rewrite.php
===================================================================
--- wp-includes/rewrite.php	(revision 18621)
+++ wp-includes/rewrite.php	(working copy)
@@ -1495,6 +1495,7 @@
 			$registration_pages['.*wp-signup.php$'] = $this->index . '?signup=true';
 			$registration_pages['.*wp-activate.php$'] = $this->index . '?activate=true';
 		}
+		$registration_pages['.*wp-register.php$'] = $this->index . '?register=true'; // Deprecated
 
 		// Post
 		$post_rewrite = $this->generate_rewrite_rules($this->permalink_structure, EP_PERMALINK);
Index: wp-register.php
===================================================================
--- wp-register.php	(revision 18621)
+++ wp-register.php	(working copy)
@@ -1,15 +0,0 @@
-<?php
-/**
- * Used to be the page which displayed the registration form.
- *
- * This file is no longer used in WordPress and is
- * deprecated.
- *
- * @package WordPress
- * @deprecated Use wp_register() to create a registration link instead
- */
-
-require('./wp-load.php');
-wp_redirect( site_url('wp-login.php?action=register') );
-exit;
-?>