Index: wp-includes/ms-functions.php
===================================================================
--- wp-includes/ms-functions.php	(revision 17979)
+++ wp-includes/ms-functions.php	(working copy)
@@ -882,8 +882,7 @@
 			__( "To activate your user, please click the following link:\n\n%s\n\nAfter you activate, you will receive *another email* with your login.\n\n" ),
 			$user, $user_email, $key, $meta
 		),
-		site_url( "wp-activate.php?key=$key" ),
-		$key
+		site_url( "wp-activate.php?key=$key" )
 	);
 	// TODO: Don't hard code activation link.
 	$subject = sprintf(
@@ -1340,7 +1339,7 @@
 	$message = $welcome_email;
 
 	if ( empty( $current_site->site_name ) )
-		$current_site->site_name = 'WordPress MU';
+		$current_site->site_name = 'WordPress';
 
 	$subject = apply_filters( 'update_welcome_subject', sprintf(__('New %1$s Site: %2$s'), $current_site->site_name, stripslashes( $title ) ) );
 	wp_mail($user->user_email, $subject, $message, $message_headers);
@@ -2073,4 +2072,4 @@
 	update_site_option( 'user_count', $count );
 }
 
-?>
\ No newline at end of file
+?>