I have to disagree with you on this as drivers are only part of the equation. X64 of which I had been testing with prior to even the XP Pro x64 release, does not have hardly any x64 native apps for it. Yes you can run many x32 apps under x64 but they run in emulation via WOW emulator, and they MUST be apps that do not require low level kernel access. This means anti-virus apps, cd / dvd burning apps, many games, etc. Including some Adobe and Roxio products that most of the population runs. I am also a beta tester for many of the big software companies so I am quite familiar with the current limitations under x64. I wish it was different but it isn't and until software companies start producing native x64 apps then I can tell you it is going to give you constant headaches.
Now of course I am referring to running a x64 MS OS whether natively on a PC or under bootcamp. I am not personally familiar with using bootcamp as I am new to Apple but unless it can magically re-code MS's OS kernel & need for native x64 apps, well then I suspect it will be the same story and running natively.
In the end if you don't believe me, just give it a try for yourself and let us know the results. I will bet money you will be wiping the x64 in favor of x32 in no time flat.