Yay! I was one of those who thought it was pretty lame that we launched the Zune without support for Vista (even though Vista is not yet available to consumers), in part because of course I'm running Vista. So it's great that Vista is now an officially supported OS for the Zune.
And, yes, I have a Zune (Brown, which I like), and yes I like it quite a lot. I managed to cram my entire music library and all of my photos, and still have 12+ GB free on the device. My only complaint so far is that the few albums that I inadvertently ripped with the WMP protection feature turned on won't play on the Zune. An aggravation, sure, but since I have the CDs, one I can remedy without too much trouble.
You can get the Zune update via Windows Update, or on the Zune.net site.