We have had our Wii Fit for five days now and I can say I am feeling it-- in my arms and my quads. The cool thing is it doesn't feel like a workout when you are actually doing it. It is just fun!
There are the traditional yoga poses and strength training exercises as well as arerobic games and balance games. Each "event" has it's own score board that ranks you with 1-4 stars and compares your scores to the other players on your Wii Fit. It creates a friendly sense of competition not only to beat Josh's scores but to beat my own. It's rather motivating.
I've found that I'm not so interested in the BMI scale and progress chart. It is too skewed to be helpful for me (at least right now). The weigh in's fluctuate too much depending on what you are wearing to show any day to day progress. I might change my mind after I have a larger window of progress to look at. There are also balance tests that result in a calculated "Wii Fit Age" based on your balance control and strength. These too are skewed. A couple days ago I was 44 because I bombed a test; yesterday I was 28. I do like that it keeps track of your play time and how much time you spend in each of the four areas. You are also rewarded for playing longer by unlocking more levels or new games.
Elijah is also able to play some of the games. He paticularly likes the running ones which he can do without any help. It's quite cute to see this little boy "running" rather crazily with a Wii remote in his pocket. It's great for those days we don't make it outside and there is a lot of energy bursting to get out of my three year olds body.
Overall, I am definitly not suffering from buyers remorse with this one. I think it is something we will use regularly and it is possible to feel (and maybe eventually see) the effects of playing.