Aside from AERO there really isn't much of a reason to upgrade since most of the other new key features will be ported to Windows XP through SP3 and individual downloads. However, now that Microsoft has finally committed to releasing Vista in time for Thanksgiving, and is willing to chope parts out if necessary in order to keep that deadline, I can safely say that the final release version will be on my computer before the end of the year. I've liked what I've seen of Vista, replicated the new layout, icons, boot screen, glass effects, etc on my Windows XP computers, and look forward to receiving my copy of Vista Beta 2 in April.
John
Will you be installing Windows Vista on your system this year?
Yes, as soon as the final version is released.
I'm already on the beta version. (How do you like it?)
After it's been out for a few months. (How long will you wait?)
No way! (Why not?)
I will buy a new system with it already installed.
I don't even have XP yet!
I'm on a Mac and will never go to the dark side.
Don't know yet.

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic