Performance is still improving quite a bit. The difference is that single threaded performance has stalled. In 5 to 10 years computers will be 4 to 8 times more powerful overall. Single threaded performance will probably only be twice as fast. However, I suspect CPUs will be 8 cores and will have integrated graphics that match today's higher end GPUs. The more interesting stuff is happening in the mobile space. Cell phone will be as powerful as today's desktops, maybe even more.