..apart from big game developers, what about GPU corporations??
They will have to evolve adapt or die, like 3Dfx and Matrox. They'll have to compete in other markets (laptop/netbook/mobile) and on other parts of the value chain (price/performance/quality/reliability). Computers are not the only things requiring GPUs. I hardly dont believe such huge cake nVidia and ATI going to drop off..
That cake is nowhere near as large as you imagine. Besides what are they going to do? Make the games themselves? I don't think so. More likely they're going to do what Ubisoft are doing. Shift their focus to consoles. I think the days of people updating their GFX cards every year to play the next game are long gone.
Especially since the console costs the same, but lasts 5 times longer. Remember in the old days, how the PC crowd would ridicule you, because all your Amiga hardware cost 5 times as much as their PC hardware, and you would ridicule them back for saying stupid things like "We get our hard drive for free"? Yeah. Imagine that.