I've been running Windows Vista SP2 for a little over a week now. Those of you without MSDN subscriptions still have a bit more to wait. We were originally told that SP2 was to be released at the end of May, but a post on TechNet [blogs.technet.com] said it would be available in the coming weeks on the Download Center (DLC) and also through Windows Update and WSUS.
There is a list of notable changes [technet.microsoft.com] in the service pack. Few of them effect my use of the OS, and I can only say that I've noticed dramatically better performance in the system search. Everything seems a lot faster than before. Other than that, SP2 hasn't made much of an impression on me.
If you're using Windows Server 2008 then you can look forward to Hyper-V virtualization will be fully integrated.
Today I just noticed that Vista SP2 was published via automatic updates. The download (389mb) went pretty fast, and the installer was alot shorter then XP SP2/3 or Win2k SP4. Haven't delved too much in what was different as I installed just before I left for work.., I'll keep my eyes open..