I personally think Vista x64 is going to be the way to go. I was running the 64bit version of the beta and RC and didn't have a problem with them on my hardware. I don't think the support for Vista x64 is going to be as scarce as it was with XP x64. The good news, for me anyway is that I'm not upgrading to Vista right away so I'll get to "wait and see" what happens.