Windows XP and 2003 (SP1) users can now download the RDP client that comes with Vista @ microsoft.com. If you don’t like it and need to go back to the original version, you can possibly uninstall it or reinstall RDP 5.2.
The new version supports widescreen/huge resolutions as well as auto-logins. There are a few other features that appear will be cool when Longhorn comes out but till then.. I have no idea what they’ll do ;)