Field Programmable Gate Arrays are totally freakin' awesome! You can fit four IBM PowerPCs onto a single Virtex chip. A tiny Virtex chip. Then you can pack a dozen chips onto a small motherboard. Wow!
An obvious step is for personal computers to implement algorithms (like video games) directly in hardware. That is, the software gets written to hardware, where it runs for a while, and then the hardware gets reprogrammed to run some other algorithm.
The FPGA design paradigm is very different from the Algol family of procedural languages. The present HDLs are very complicated. A simpler language is going to be needed if an FPGA computing revolution is ahead.
The difficult thing for many people to wrap their heads around is the massively parallel nature of FPGAs. If you've never hacked with 74-series logic, you've got a steep learning curve ahead of you.
The next trick is waiting for the shakedown of FPGA architectures. Having distributed memory, clocks, and multipliers completely transcends the idea of a Central Processing Unit.