I just spent an evening with WiiFit and I have to admit that my hype level was way higher then my real life impression.
The WiiFit board is a large chunk of plastic, it feels cheap, it looks cheap and it in all probability is cheap. The games that come with it feel cheap, look cheap and play cheap.
The problem is not the board itself, which I think is a great idea, but the level of quality of the board and it's games. It's just pitiful...
The quality is not in the same room as the Wii and Wii sports, they don't even seem to be related. If the Wii is an ipod then WiiFit is a Soviet world war 2 tank covered in rust. Nintendo just looks like a greedy bully when I look at WiiFit. I hope for Wii's sake that the coming snowboard and skateboard games make a lot better use of the board.
Because even though my impression is not even remotely good, the balance board is a good idea. Especially for games lite SSX and its like.