Yeah, kids find it pretty funny. Even my two year old enjoyed it. It was incredibly qute watching her moving around the trampoline and she repeatedly looked down on her hand to see if the Eyepet actually was there.
Still this game is no competition to Lego Rockband in our home right now. That´s a very well crafted game towards kids in the range of 5-10 years and a game the parents can enjoy as well at the same time at a different difficulty. Feels far more constructive than petting virtual animals or shooting virtual zombies in my opinion.
Edit: I should add that I think Eyepet worked far better with the 480p camera than what I what I expected, I was expecting it look more low res than what it actually did, still a HD camera would be nice.
I also agree with Arwin that it will probably work far better with the upcoming wand, ti is pretty easy to accidentally tilt the card so the camera can´t detect it, that could easily be avoided with the wand.