The console industry's profit margins have really started to dry up. There won't be a new console (other than perhaps a Wii HD, probably less powerful than, or at best on par with, the existing PS360) by 2012 to up the graphics bar.
Console generations, from here on out, will very likely be much longer in duration. The industry has matured, and expecting it to continue forward, as it, and the tech sector, did during its golden/early years, is folly.
In any case, even the highest-end GPUs, by 2012, will not dramatically improve anything but framerates at 1080p by then. Hot new graphics hardware is severely affected by diminishing returns, and 1440p (or higher rez) TVs aren't coming anytime soon (you can hardly tell the difference between 1080p and 1440p at more than 30 cm away from a giant screen anyway).
You can have a blazingly fast GPU, and you still need to supply the memory for the massive textures it could use (makes console expensive), and the art team to make those textures, as well as the disc space.
