This article at The Inquirer points to an interview with Chief Scientist at NVIDIA, David Kirk, saying that because game developers will no be spending more time working on utilizing the multiple cores of the CPU, improvements in graphics and the utilization of the GPU will slow down.  Interestingly, this is a very similar statement to what we heard echoed by John Carmack at his recent keynote at this year’s Quakecon event.  Citing the use of multiple cores in the consoles and in the PC, Carmack thought that it make the development more complex than necessary for the current state of hardware. 
CHIEF SCIENTIST David Kirk told the Hot Chips conference at Stanford University that programming technology faces problems because of multithreading and multicore introductions.

The EE Times reported Kirk as saying that chip architects are moving quickly to multicore and multithreading designs but that could mean a slowdown to graphics performance.

CPU manufacturers like Intel are positioning dual core and multicore processors as if they doubled the “brain power” but Kirk seems to be suggesting graphics processors are quite a bit brainier than Intel or AMD dual core chips.