Though just rumors at the moment, there has been some talk in some computer journals that they are hearing that Vista's Service Pack 1 is going to be released in the next few weeks. One reported that Microsoft is aiming for February 15th for the *much anticipated* release. I, myself, have seen these rumblings in both Wired and Computer World magazines.
Though the RC1 build has been out for some time, I have always been rather wary of installing a beta or an RC build of a service pack. I really worry about uninstalling such a beast and what does that do to the final install that you make. I am really a believer that you should only be working with beta versions of service packs in virtual images that can be blown away.
I can't tell you how excited I am to be getting this service pack - as many others are for sure. I once heard that this service pack includes fixes for more than 25,000 bugs. Wow.