Microsoft has released the RTM version of SP2 for both Windows Vista and Windows Server 2008. They have an iso file that includes the x86 and x64 versions for both operating systems in several languages. It is up on both TechNet and MSDN Subscribers.
The bigger news is Windows 7 Release Candidate, which went up on both TechNet and MSDN Subscribers this morning. Earlier in the day, the MSDN download site was crumbling under the pressure, while TechNet seemed to be doing better. They both seem to be doing fine now.