Yeah, I've got one of those things. I think they've brought out another game for the Eyetoy which is dance related.
Personally, I prefer the dancing games using the mats. Even better to get rid of the Xmas excess!
In fact, I've even figured out a way of connecting my PS2 dancing mats to my PC so that I can use them with this great free program:
Stepmania
Not everyone's cup of tea but if you've got kids who love those dancing games and a PC, then you'll save loads of money checking out the link above!