I think you should try out Wii Fit before you actually start calling it a fad or anything. I bought my copy of it about 2 weeks ago and it's been my most played "game" ever since I bought it.
I'm not overweight or anything(normal BMI rating), but Wii Fit has made me more conscious about my overall health. Those strength exercises can be really difficult, but as you do them more you start to get better and better gaining strength. Even my gf tried it out and had fun with it (although she's underweight according to the BMI!)
Try it out before you write it off as a fad. You may be surprised!
starcraft: "I and every PS3 fanboy alive are waiting for Versus more than FFXIII.
Me since the games were revealed, the fanboys since E3." 
Skeeuk: "playstation 3 is the ultimate in gaming acceleration"
