Index: wp-login.php
===================================================================
--- wp-login.php	(revision 5996)
+++ wp-login.php	(working copy)
@@ -237,7 +237,7 @@
 		$errors = apply_filters( 'registration_errors', $errors );
 
 		if ( empty( $errors ) ) {
-			$user_pass = substr( md5( uniqid( microtime() ) ), 0, 7);
+			$user_pass = apply_filters( 'pre_user_pass', substr( md5( uniqid( microtime() ) ), 0, 7) );
 
 			$user_id = wp_create_user( $user_login, $user_pass, $user_email );
 			if ( !$user_id )