NV and ATI, otoh, are still innovating and each product cycle is better than the last in some easily measurable way. I don't see things coming to the point that they did for open source software to gain a foothold for a while now.
I think once either NV or ATI goes out of business or drops out of the 3D race, and the remaining player continues selling the old products for the same prices, might we see people start to take matters into their own hands. By then, more powerful FPGAs and VHDL simulators will be available, not to mention more people with the requisite knowledge. For now, we sit and wait and let the market mature to the point where community-based hardware development can take over.