Fwiw, Microsoft actually anticpated that some people wouldn’t be thrilled with the Vista experience, and made it fairly easy to “downgrade” to XP. It’s completely legal, they support it, and you can upgrade to Vista again later if you want. This way, you don’t have to screw around with a dual boot system (although it doesn’t help the driver issue). Here’s a link with more info:
http://download.microsoft.com/download/5/f/4/5f4c83d3-833e-4f11-8cbd-699b0c164182/royaltyoemreferencesheet.pdf