I thought this was already mentioned, actually. I'm assuming you mean WarioWare: Smooth Moves.
It would make sense that several Nintendo-developed games (and perhaps some third-party Wii games) would make use of the Miis for them to dedicate a WiiChannel for them. (I imagine they may be useable in Animal Crossing for the Wii, and other games that may use totally different styles could at least use Mii data to come up with an approximation that fits its style.)