Shortly after getting our Wii, Jenn managed to find a Wii Fit at Walmart in another interesting story. She went to Walmart and asked if they had any Wii Fits in and wasn't laughed at... instead the lady stated that they had some in the back that they didn't intend on putting out on shelves. Sounds like some unhappy workers are slackin off :-P
Jenn ended up getting two, just in case someone we knew wanted one and we knew how insane the demand is.
Onto the fun... Wii Fit is a game paired with the Nintendo Balance Board in such a way that it works on throwing even more gameplay conventions out the window. It challenges players to be conscious about weight and balance in such a way that it encourages (and itself forces*) activity.
The caveat to the activity it encourages/forces is the fact that people can "cheat" the system... but then it's just a wasted novelty. One can have a little extra fun in the "Island Run" by jerking the Wiimote up and down extra fast near the beginning to get your Mii to follow dogs rather than another Mii, one of which makes you jump off a cliff in your run.
All in all, I have to say this was a sound investment. We play almost every night and track our weight (not an entirely accurate measurement, but it shows trends). It has plenty of activities that attempt to enhance strength and balance as well as aerobics and yoga. I'd probably never do something like Yoga or step aerobics in a normal setting, but with the Wii Fit, I've found them to be somewhat fun and physically challenging.
If anyone wants to buy the extra Wii Fit off of me, just let me know via email or discussion... I'll be sure to put in the discussion if it's sold...