Well, nothing lasts forever. I, too, hope that someday we will have nVidia cards with open drivers. My understanding is that their geforce line is too patent-encumbered for that to ever happen to them (they pretty much went full-Microsoft during the original Xbox era) but that they more or less own their mobile (as in handheld) GPUs outright, and if they ever become the basis for a desktop product, we might see an open version of those drivers. Nouveau is pretty much unusable for a lot of users, and useless for even more.
Problem is, only a subset of ATI cards are well-supported by the FOSS driver, and the official drivers are poop. When more of the cards are supported and it takes less time for the cards to be supported, maybe I will consider ATI cards again. But every time I do, I regret it deeply...