The card I'm concerned about for Open GL is the one that came in my computer, the Radeon. If Apple follows in the old Apple way, Aple will make sure that I have drivers for my card. If that card works, it seems reasonable that my other ATI card would work as well.
I'm going to give Apple some time and see what they come up with for me, I feel more confident in getting a solution from them than from ATI.