Microsoft has made the BETA release of Service Pack 1 for Windows 7 and Windows Server 2008 R2 publicly available to TechNet, BizSpark and MSDN subscribers.
If you’re eager on testing the latest build for Windows 7 and Windows Server 2008 R2, head to the MSDN download page. Otherwise (if you’re a consumer), just wait for the final version.
No new features will be brought to Windows 7 in the upcoming service pack, just bug fixes and general improvements. Windows Server 2008 R2 SP1, on the other hand, brings Virtual Desktop Infrastructure enhancements that enable hardware-accelerated 3D graphics and video playback over a Remote Desktop Connection.
via Windows Team Blog, TechNet