CPUs are currently limited though. The problem is cooling, mostly. Modern processors are approaching the threshhold of practicality in terms of cooling. Sure, you could set a liquid nitrogen stack on your processor, but I don't think many people will go for that. Plus, you can only stuff so much copper and gold into a silicon brick.
Say hello to quantum computing. A radically different way of processing data that would be better explained with an article (Wikipedia makes me pee my pants):
