Again, not to dash Sean's hopes ( I've heard of some people doing some awfully amazinging things with incredible disabilities) but I want to throw out again that we may be setting the bar a little high here -
I.e. - Basically a console system and controller with 8 analog buttons, a d-pad, and two analog joysticks (plus two additional buttons) may be a little much to expect for someone with wrist movement, but limited hand movement and limited sensation of pressure being applied.
OTOH, If you basically took 1HSC's design and made it with two digital joysticks and an encoder, you would have perfect control for Joust, Robotron, Galaga, PacMan, Metal Slug, etc.
Sean - Do not take this the wrong way. I have full use of my hands and I realized long ago I lacked the co-ordination for games with more than really one joystick and two buttons, so I stick to games like the above and avoid Street Fighter, etc.