I want people futzing with Caster and other titles with Intel, NVidia, AND AMD GPUs. Sure, it's closed source- but there's some FOSS-ed things that I'm working with here that I'm going to hold the same position with. But then, I'm probably the exception there and not the norm.
Anyway, got sidetracked there for a bit. To the real issue. I don't think ATI drivers themselves are what's preventing any commercial gaming in Linux. That seems like an excuse not to bring games to Linux.
Once you start bringing big commercial games to Linux you inevitably will bring everything that comes with it, which in short equals to money. You think AMD won't want a piece of that pie? If Linux gaming starts getting as big as Windows gaming, then AMD will start doing whatever it deems necessary for it to secure a place in that new market.
If commercial game developers keep stalling and offering excuses, then things won't change from how they are now. Entrepreneurship in the industry is all but dead though, so the sad reality is that aside from a miracle, we will never see the big commercialization of gaming in the Linux side of things like we see with Windows. If anything, Linux gaming will remain the realm of hobbyists and small indie studios.