I agree that it needs to move to pure x64.
This would make it much easier on consumers who have 2 versions to choose from and don't know which to pick.
Businesses using x32 computers shouldn't upgrade to the latest and greatest new OS anyways, and if they want to, buying a whole new computer makes more sense (in this regard).
I would love to see only x64. The other great reason would be that more and more programs would be natively x64, thus increasing performance as a whole.
Even better would be multi-core support as a norm.