ALREADY? They just released 7 and there's already a service pack (in Beta)
Windows Server 2008 R2 Operating System
EDIT: After being neg repped for this I decided to put some specifics here. It is a Beta SP1 for 2008 R2 and Windows 7 combined. You must be running both to use it as it adds/enhances some features such as Virtual Desktop Infrastructure (VDI) and RemoteFX.