Terminal Services client v6.0 released
This is now available to download for Windows 2003 & XP.
There are quite a few new features - more info is over at the terminal services team blog: https://blogs.msdn.com/ts/archive/2006/11/29/remote-desktop-connection-terminal-services-client-6-0-for-windows-xp-and-windows-server-2003-english-only-released.aspx