Microsoft announced today the Release Candidate (RC) of Windows 7 and Windows Server 2008 R2 Service Pack 1 (SP1) to the public. For those unaware of how these software rollouts “work,” the RC release generally signals that a final build is almost ready. The only new features added to the SP1 are the Windows Server 2008 R2-related virtualization technologies, Dynamic Memory and RemoteFX, and while Windows 7 SP1 will enable PCs to take advantage of these server-based features to provide a more scalable and richer VDI experience for end users, there are no additional new features specific to Windows 7.
If you do choose to install this Release Candidate make sure to backup your system. Microsoft usually makes you uninstall the RC before installing the final build of the service pack.