the wiimote + nunchuck is not much different then a regular controller. Joystick, 4 main face buttons(the d-pad) and 3 shoulder buttons, start+ and select-, plus theres 1 and 2 and A. You could play virtually any regular game on a wii-mote. The classic controller only improves 2d snes/nes games because of the d-pad, but your standard modern game could be made just fine, and actually you have a lot more room to play around with control schemes as a developer than you did with the Gamecube.
I wouldn't paint Nintendo as a vulnerable loser either, they have the market share, and sure they have had problems with appealing to the hardcore demographic, but this isn't as different from the Gamecube generation as people would like to paint. Wiifit, and the casual games are the modern version of Animal Crossing and Mario Party. They are filler. They make money while the pet projects cook. I would say Nintendo has done better this generation as a developer than they did last. I don't have as many games, but thats because 3rd parties have dropped to their last brancell. Mario Galaxy is better than Mario Sunshine, Twilight Princess was a gamecube game(a good one, if you didn't like it, its usually because you were not a Zelda newbie). Mario Galaxy 2 is coming out, and a new Zelda is supposed to come out this year(some are skeptical, but i keep track of zelda news and this one was mentioned during TP development).