
The page states that the release will be available throughout at least June 2009 and will expire in June 2010. Microsoft states that the final version of Windows 7 should be released prior to that date. They encourage for all users upgrading to back up their data and do not recommend the OS for use on a main/primary computer.
The Windows 7 RC will be available in 5 languages: English, German, Japanese, French, and Spanish. Hindi/Arabic support will not be available until Windows 7 RTM's.
The Windows 7 RC is expected to be available for download in May or earlier.