Chris is right in theory. The EyeToy and EyeToy: Play have the potential to be "the killer app that can draw people who have never played a videogame in their life before towards the PlayStation 2." But in practice, there are still some problems preventing both the peripheral and the game from becoming a revolution in the way we play games.
First off, while the simplicity of EyeToy: Play's games is initially a boon to getting non-gamers to play, it eventually becomes a hindrance to any long-term enjoyment of the game. In my experience showing off the game to my college-aged friends, both hardcore gamer and otherwise, the reactions progressed steadily from skepticism to mild interest to boredom. As soon as the novelty of seeing themselves on screen wore off, everyone in the group seemed to collectively shrug and say, "Is this all there is to it?"
Waving your arms to spin plates and knock out ninjas is all well and good, but after about 10 minutes of straight play, each of the mini-games gets a bit tiresome. The variable difficulty levels don't make up for the fact that washing 100 windows feels a lot like washing one window 100 times only with progressively sagging arms.
In the end, it's a lack of mentally engaging gameplay more than a lack of complexity that really hurts EyeToy: Play. Even the simplest of the classic games from "the early Atari era," that Chris mentions had advanced tactics that separated the pro from the newbie. There was always room to grow: a new ghost clustering pattern in Pac-man or a method to rescue all the family members in a wave of Robotron 2084. That's why they're classics, because they required tight concentration in addition to tight reflexes.
With EyeToy: Play all that really matters are dexterity and muscle strength. Turn off your brain, wave your arms as fast as possible and high score!
What the EyeToy really needs is its own Tetris: a classic, must-own title that's simple to learn but tough to master that incorporates elements of both fast-paced and more thoughtful games that both gamers and the non-gamers will be unable to resist.
EyeToy: Play contains evidence of the potential for such games, but never quite manages to reach that potential. There's something missing that prevents any of the mini-games from becoming more than interesting technology demos. I hope it won't be long before some developer finds that missing piece and makes the EyeToy into the true revolution it could be.