If you're wanting to run Windows only, then why not go with some of the already supported Intel Core Duo laptops out there from PC manufacturers? Personally, I think the HP dv100t and the Dell E1705 are rather good as Windows machines (the former I've read about and it's gotten good reviews, and the latter my wife owns and I can speak from experience).
I myself would prefer a MacBook Pro but for OS X. When it's officially supported to have Windows apps running transparently on OS X, then I might do that if there are no OS X equivalents or ports.