8800 & 8600 Cards in the Same System?

Hi all, just a situation I have been puzzling over - is the following possible?

I realise that the 8800 cards are far superior to the 8600 series, but that the newer 8600 cards have the enhanced hardware decoder for HD-DVD/Blu-Ray content, to take the strain off the CPU.

My question is, could you run an 8800 & 8600 card in the same system and make the 8800 the primary display adaptor for games and swap to the 8600 for HD playback? :?

I also realise an new ATi card would do both, but I'm not sold on their framerates... or their power/heat for that matter

YES
you can.

Pretty simple, even. Use partition magic or a similar program to carve out another partition on your hard drive. Install windows again to that partition. (quicker and easier if you have a disk image of a clean OS install).

For the partition that has the old windows, DISABLE the 8600 card in device manager. Use that copy of windows for gaming and stuff.

For the partition that has the new windows, only install the stuff you need for video playback - windows MCE, ect. DISABLE the 8800 card.