Update

Well, obviously I've lost my enthusiasm for keeping this site and blog updated. I did get the arduino working and made a post on the arduino forum about it. Chad over at windmeadow.com has done something similar; see this post for arduino-as-peripheral and this one for arduino-as-nunchuk-master.

On the hardware side I threw together a harness out of ShapeLock and mounted eight pinball microswitches. The wiimote would slide into place and the arduino could be bolted on. A pretty ugly monstrosity to be sure, but it more-or-less worked. I got bored with the project before getting around to writing a keymap.