havent you seen the reports of that french party (alchemie 07 i guess)? there are not only screenshots but videos showing video-thumbnails in ambient, cube3d and stuff like that. those videos available even on youtube. what else do you want to see (except for the real thing of course)?

btw i like ambient screenshots a lot, often browse them in various forums (well, its kinda past now as i've seen almost all of them:), but as developer's ambients are quite boring, i prefer wait when users can post theirs:)