I think it's called motion averaging, or something to that degree. Ironically m$ pioneered that one, but for the opposite reason (realistic force-feedback). I think wii homebrew will happen, but it's going to be a sloow journey. You've gotta remember, the only system that had quick, fullfilling homebrew was the xbox, and that is because code-wise it is basically a pc. We don't have a clue what the wii os is based on (though most speculate it's linux based.)
But using wiimotes, on the pc is also a very useful tool for hacks. I've already posted a couple of scripts in the software forum, one for starwars yokes, and one for sonic blast man (a game where you punched a punching bag). Scripts that use the ir tracking still need work (Nobody has made one that it's pixel accurate yet.), but I've played around with a "mame script" that somebody made, and found it very serviceable for playing games like terminator 2 in mame. I think it is particularly exciting for people in our particular hobby as controls that are impractical to have on a mame cab (yokes, analog mounted guns, ect..) can be recreated using motion guestures, a wiimote, and possibly a custom shell for the controller. Also something of note is the generic controller companies out there have jumped on the band-wagon. I ran across a 6 axis controller for the pc yesterday for under 30 bucks. Mind you I've stressed how stupid a 6 axis controller is unless it's in a generic shape (see any rant I've made about the ps3) but this means we have a cheap source of accelerometers.