Great peripheral gaming.
Eyetoy, while obviously for younger gamers, is something that anyone - and I mean anyone - can have a go at. And they will. It's meant to be a party game, in that - Nintendo again - games such as Super Smash Brothers Melee are meant to be played multiplayer. Bring anyone around to your house and set it up and within minutes they'll be having the time of their lives.
Aside from the obvious multiplayer fun you can have, however, Eyetoy tends to lack a few things. Once you've gotten the high score, etc, what reason is there for you to continue playing the game? Some of the games, such as Rocket Rumble, can be unnecessarily hard, a problem for the kids that will beg their parents for this game.
The camera can also sometimes be an issue - like the old Game Boy Colour screens, if you don't get them in the exact light you're going to have some problems playing. Generally it's best to set up your camera NOT facing a window and perhaps stick on the lights.
Aside from the technical issues and shortness of it, though, Eyetoy is fun to play and anyone can play it. It may not last, but the short experience definitely is sweet.