This week Microsoft released the Release Candidate (RC) of Windows 7 and Server 2008 R2 Service Pack 1. Some companies follow the rule of not deploying a new Windows operating system before the release of the first Service Pack, however for Windows 7 there is simply no need for postponing deployments because SP1 doesn’t add any new features but only addresses some minor usability issues. On the Windows client operating system side SP1 is basically a rollup of hotfixes and security updates released since Windows 7 RTM.
According to the Microsoft blog, SP1 is expected to be released in the first quarter of 2011. Personally I would recommend companies to just continue their deployments with Windows 7 RTM, but take into account a slightly longer image maintenance cycle when SP1 is being released, so that there is enough time to rebuild the image with SP1 and conduct the necessary testing activities.
Additional Information:
Documentation for Windows 7 and Windows Server 2008 R2 Service Pack 1 Release Candidate
Windows 7 and Windows Server 2008 R2 Service Pack 1 Release Candidate Frequently Asked Questions