The last beta build of Windows Vista has been released to the public. If you’re developing any applications where your intended audience will be using Windows Vista, then this is the time to download Windows Vista before it goes RTM (Released to Manufactures). Any applications that run on Vista RC1/RC2 (Release Candidate), will be certain to work with the RTM version that’s expected to be released very soon.
Please be sure to check out Channel9’s. There you will find quite a few interesting videos on UAC, and many other Vista related programming screencasts.