I just installed Vista on my VERY lowly specced Tablet PC (Centrino 1Ghz Ultra Long battery Life Panasonic Toughbook)... and bugger me if Vista isn't screamingly fast on it. At least as fast as XP. Vista suddenly seems really usable... and ready to hit the shelves! *rubs hands with glee*
No Aero Glass of course due to a basic Intel Video card. But who cares. Vista still looks amazing on it.
I'm about to scoot off to bed to play with it for a bit... got a big gym session in the morning.
No WiFi drivers yet so off to plug into my hard wire and see if Windows Update gives me any love....