Google TV's Youtube app has a screen saver. It kicks in every 10 minutes or so. You probably won't notice this (since most Youtube videos are under 10 minutes) unless you buy a Youtube movie, which I did. Ha. Dismay.
On the other hand, if on the same Google TV you browse to youtube.com/movies, and start watching a movie, the screen saver doesn't kick in. Sadly though, in this mode the "full screen" key on the massively overdesigned keyboard doesn't function, so you have the movie in a little box in the middle of your giant TV screen. +1, guys, +1. (After some experimentation I learned that you can pagedown - yes, the Google TV keyboard has a mouse but no scrollwheel - and then mouseover the video and press the otherwise-invisible Youtube fullscreen button, just like on a real web browser.)
The good news: Google TV will be totally useful as a conversation starter at parties, if what you like doing at parties is ranting about what happens to your project when it has absolutely no product management focus. Hmm, that sounds terrible. Remind me not to throw any parties.