From what I'm reading,
3D gaming is not really supported. Sure you can run Age of Empires, but don't expect more than that. Like I mentioned, I couldn't even get a 3D editor to run.
If you look in the device manager, you'll find only virtual parts. XP mode uses "Virtual PC Integration Components S3 Trio32/64" for graphics, at least in the beta build I'm running.
You can assign more memory to the VM, possibility to emulate multiple HDs (they are basically images stored on the physical machine's HDs), assign physical DVD-drive to be used, etc.

It's aimed at corporate use, not home users. It's included from "Pro" edition up.