So I got my nVidia 7900gt back from the shop, the 8500gt I picked up as a "keep me going" is of course outside the return policy so I figured I'd make the best of it...

I fired up Vista with both cards installed, no problems as far as actually running WoW with two different video cards, however the performance issues that plauged me in XP without horizontal span are VERY present with multiple video cards. With one wow on the 7900gt and two on the 8500gt I get no better than 30fps anywhere. Once I flip the monitor back to the 7900gt I'm back to 30+fps on the main screen with 50-100fps on the smaller lower settings windows...

I would guess there is a chance for this to work with matched video cards, perhaps it's just the fact that I've got an 8000 series and a 7000 series in the same system thats the hitch...