lots of people have, and the results are mixed. if you want to do anything along the lines of backing up your movies/music or anything else that DRM technology and corporate groups are against, stay the heck away from Vista.
if you want to game (the only real reason to get Vista), the best setup will be to use multiple machines--one for your daily tasks, audio/video work, etc, with a previous version of Windows, Linux, or even a Mac OS on it, and one for gaming with Vista on it
