Start out slow I got 2 copies of Vista and am putting one on my laptop and will get used to it there. Then later I move my SLI system to Vista. No hurry there yet.
I've got it on my Inspiron E1505 and I'm loving it. Lots of little things that are different, but it "feels" far smoother on this box than XP ever did. Battery life breaks even essentially, maybe better life in Vista when using wireless, but probably better life under XP when playing games. Not a big worry either way.
Now, my "main rig" is a different story. I'm most definitely waiting it out until I see some newer drivers.