Not yet... I"m on Vista 32 right now. I went back to Vista 32 awhile ago so I could play with the ATI Gaming Fusion beta. Now the release version includes a 64 bit version.
I plan on re-loading in the next week or so after I play some more. (I may also try 8Gb of ram just for fun... but I suspect I'd have to slow it down a bit. If not that would be very cool.)
I suspect that I will be able to very easily get 3.6-3.7Ghz even with Vista 64. (I believe I can get 3.8-3.9 on Vista 32. I SOOOOO want to buy water cooling and a pretty case for it.)
EDIT: OMG::: Just upped the NB to 2.6Ghz in bios... rebooted... tested... it gained me almost 1Gb/s memory bandwidtch and the latency went from 56 to 49ns. (Sadly I had to back it the NB back to 2.4Ghz... so only 800Mhz/s faster and 50.5 nm latencty.)

