I am second about virtual machines. They are maybe still bad with video emulation (I never heard about VM that can emulate even GeForce2 up to "acceleration" level, and I would be glad to know about that), but otherwise they are quite trustworthy. So it's don't needed to have anything "real" older than XP.
XP itself
can work with multiple cores - but it's
programs that must use it. Any modern program can utilize multi-core on XP, but if, say, System Shock 2 was never aware of several cores, it will not use it, no matter what.
Same for other games for that era.
Otherwise, it looks fine. Slightly low HDDs, as for my tastes (I have 2Gb as main disk and 1Gb for backup - and it's too low! Low!
, but can be just fine for you, I suppose.