I absolutely LOVE my wii fit!
I got our Wii fit recently and really think it does a good job of making you sweat. I'm not sure if it works all your muscles but it sure does do a great job on cardio if you play tennis etc.
The yoga program is a lot of fun and the more you do the more you unlock. Even the balancing games get you moving. The push ups, etc, really work your whole body.
It's hard to find time to play with a two year old but so far I really like it.
Cover
Does anyone have the cover for the wii fit and do you think it is needed???