Wasn't GameCube initially sold at a small profit? I see not reason to not expect the same for the Wii.
Controller prices could definitely be a problem. Personally, I like to own 4 controllers. (I bought 4 at launch for GCN.) At launch, GCN's wired controllers were $35 (dropped to $25 when the Wavebird took over the $35 price point). The Wii's controllers are much more complex and have an unknown number of attachments included (at least the nunchuk, probably the shell, maybe more we don't know about). I would not be completely surprised to see $40-$45 controllers, but that is approaching the price of a game. Hopefully, Nintendo will manage a $35 or lower controller price (especially if they want to encourage multiplayer), but I'm not counting on it.