From my experience unless you have not got my Minimum specs: 3.2ghz, 2gig rams, 7800GT then use Vlite method to install Vista. I have Vista Ultimate running nicely on this machine.
http://www.vlite.net/
With Vlite installation method I have a dual setup with vista/xp. Vista runs nicely on this oldish rig - 2.6ghz, 2gigsram, 6600gtx
you choose to take the bloatware out. Your end up with a Vista OS on steroids.
To early to say Vista is out, its still going through its teething stages plus they got to stop ripping of the buyers - Vista on a Compaq/HP PC running 512ram "Now experinece the autimate entertainment in your living room" :rotfl:
I blame these leechers in there PC shops selling crap spec PCs with Vista on it.
A good tech would refuse to sell them in his shop.