Absolutely. Has CPU speed increased even two fold over the past five years? For a long time there was little point in upgrading CPU on PC above whatever i7 you already had. The main performance gains at the top end is stupid die sizes and number of cores.
The only way to go even faster is to go even simpler, meaning higher peak possibilities but lower peak utilisation,
a la Cell. There's no point doing that. Those workloads, put on GPU. CPU is there for 'messy' workloads.
Perhaps it's time to ditch the idea of Central and Graphics processors, and instead define them by workloads they are suited to? Wide Parallel Processor versus Random Access Processor?