(If you haven't already...) From what I understand, and from *several* sources, (1) Vista doesn't have all that much to offer over XP over "prettiness", (2) all the bugs aren't worked out yet, and (3) unless you have a truly souped-up computer, Vista may really bog you down. So, until and unless you buy a new computer with Vista pre-installed, there should be no rush.

Windows Vista is released to the public sometime in January 2007. If you're an MSDN subscriber, you can download it now.