I've been playing with an RPI. So far there's one thing in particular that irks me: its power arrangement. 1A+ @ 5V over µUSB? Really?
No me gusta.
So I've got an idea to design a "cape" (or whatever you call RPI add-ons) to sit on the expansion interface. The board will be as small as possible, but will have a 2.1mm barrel jack and take in 6-12 VDC and supply up to 2A @ 5V regulated by a LM3485 buck converter. Mischief managed.
The board will have a "long tail" DIP jack to mount on the bottom which will allow you to stack other expansion boards on top.