I'd say this is one of the most useful posts ever for people thinking of buying a PC: How many Intel CPUs will fail the XP Mode test in Windows 7?.
What Ed Bott has done is go through the somewhat obscure Intel info and identify which chips will run XP in virtual mode under Windows 7. There is no method to the Intel madness: more expensive doesn't inevitably mean that your CPU will have the needed virtualization extensions (Intel VT), nor does more cores. You just have to know. And now you can.
By blind dumb luck, the computer I'm writing this on, a Dell Precision T3400 — a sort of stopgap refurbished machine I bought in a hurry when my old one croaked a few months ago — has a E6850 on it, so I'm OK in the unlikely event I upgrade from XT.
That said, my plan if and when I get a RoundTuit, is to test out the really nifty-looking new release of Ubuntu, with a Virtual Box, and see how that box handles Wordperfect. If it's fast and smooth, that's where I'm headed if the guest can share the clipboard with the host.
Clipboard sharing works great with XP as host and Ubuntu as guest. Only complaint is that sharing a directory doesn't work out of the box, and sharing a USB drive runs into hardware issues. (I gather you lose 3D in the guest, but I am not a gamer, so I can live with that.)