Get Win7 Ultimate. There's a new VPC coming out..and with Win Ultimate you get a free XP Virtual Image.

>I've installed WIn 7 RC on a VM in my XP machine. But, it's the 32 bit version running in a virtual environment. So I've used the OS, but now way to know any pain points of the 64 bit version until I install it on the bare metal. That will pretty much commit me to doing it all the way. There's no going back.
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>Will Win7 offer to create a boot manager if I install it to the existing XP machine? That would allow me to keep my XP machine alive, but it would cause the HD to get partitioned which would be a pain to deal with from now on. I assume after the first few weeks, I'll be in Win7 happy land and never look back, but then my HD would be all messed up with that old XP parition laying around.