I'm gonna have to go on board and say Wii Fit is one of the best moves Nintendo's ever done. There are massive untapped markets, not only those who are into fad weight loss products, but in fitness freaks of all varieties. Yoga itself is an absolutely huge market, and I can see tons of people (most likely woman) buying a product that gives them interaction for things like yoga and light aerobics.
Video games used as fitness programs was inevitable and I think Nintendo is going to make a killing exploiting it first. Wii Fit is just a more interactive version of all the fitness video's people buy.
On top of that, if anyone actually supports outside of nintendo, it offers all sorts of possibilities for core games. Skateboarding/surfing/snowboarding, certain sports titles (though I can't think of specific examples), on rail FPS's ( Anyone ever played the rail shooter game Police 911?), racing games (use the board as pedals maybe?), the possibilities are there. Games only available in arcades with expensive machines could become possible on a console, similar to how dance dance revolution eventually showed up on consoles.







