According to this paragraph:
For virtual desktops deployed on top
of the Hyper-V virtualization platform
in Windows Server 2008 R2 SP1,
graphics hardware-assisted rendering
of the screen content on the VDI host
will ensure that even the most
advanced applications today and
tomorrow will “just work”.
The answer to your question is: yes, but I'm guessing there will be caveats (there always are).
You can find their hardware considerations here. The Hyper-V server will require a DirectX 10 compatible graphics card (Which could be a pain because 2008 R2 has a few known issues with the Hyper-V role and high-end graphics cards. We'll see if they've been fixed in SP1). Looks like you're going to need a LOT of video ram if you want multiple sessions at anything but 1024x768, and if you want to do live migration you'll need identical GPUs.