I tried something similar once with a new motherboard, and it didn't work. The problem seemed to be that the XP installation I was using wasn't compatible with the new chipset on the new motherboard (it can handle being transferred to a new hard disk at least, but the chipset it couldn't). And that was a fairly similar motherboard, whereas you will be using a radically different motherboard and chipset. But perhaps some expert here will have a workaround for that?
I've done this in the past, but it can be rather involved, since as you say many of the motherboard devices on the previous computer will now be absent, while plenty of new ones will have appeared on the new PC.
However, if you've got as you say 'hundreds' of plug-ins on the old computer along with Cubase 2.2 that may not be happy under the new hardware then it's worth trying to remove references to the old hardware using a clean mode Registry clearout while the partition is still on the older PC, and then rebooting it on the new one.
I described how to do this in PC Notes June 2004 after changing over a motherboard in my own PC at the time, and it worked well enough for me to continue using this partition for several years longer
Basically you need to delete ANY driver relating to motherboard components or additional expansion cards and the like that won't be on the new machine. Then save the partition and restore it to your new PC and boot from that.
During this boot loads of new motherboard devices will be discovered, and this is where things could get tricky, since although you could insert your Windows XP CD to find the drivers, a modern PC is likely to have quite a few that don't have drivers on that CD, although they will on a Windows 7 Disk but won't be compatible with Windows XP.
Personally I'd get all your project data saved separately, and back up the contents of your old vstplugins folder to restore onto the new machine if possible.
Scramble's idea of rendering the existing projects so that their plug-in contributions are captured as well would certainly make things much easier though, since you can then import the rendered audio data into a newer sequencer and not need the old plug-ins