I like the idea of building off current technology. Adding a PC104 or mini-itx computer to interface with the current IFI controller would be a great way to keep the low-level drivers and expand on high level programming. I thought the
Adam-Bots Co-Processor platform was a start in the right direction.
In terms of the actual hardware,
Royal Assualt's (357) "Schubox" PCB of a board to inteface to IFI RC is a great idea. I think FIRST should sell a simplified PCB design (like the VEX controller). Letting teams do their own PCB design would bring down the cost of Electronics tremendously.