The general public will be able to test out an official beta version of Service Pack 1 for Windows 7 and Windows Server 2008 R2 by the end of next month but some lucky testers won't have to wait that much as they are getting invites from Microsoft itself.
Currently being delivered to the most helpful testers of previous Windows programs, the invites provide early access to the SP1 beta which will be available in five languages - English, German, Japanese, French and Spanish and include all security updates released to date, improved HDMI audio device performance, more efficient power consumption, as well as Server-specific tools like Remote FX (enabling a rich 3D graphical experience for remote users) and Dynamic Memory (gives more control to adjust memory usage without sacrificing performance).
The full Windows 7 / Windows Server 2008 R2 SP1 will be released later this year.
Source: TechConnect