According to this video on Gear Live (check it out soon as I'm sure it'll be taken down any moment now), it looks like Uno will be the first game to support the XBox 360 Camera.
The one disapointing thing that the video shows though is that Texas Hold'em, a game that would have more to gain from it, doesn't support it.

Comments
they said texas holdem will support the camera as well
I guess they just havent added the camera support yet, or they forgot to put the camera icon on there
very weird
there is an artice at xboxic where they state that SF2 and cloning clyde will be the next xbla titles released
http://www.xboxic.com/news/741
but cloning clyde will be released after E3, so its at least 3 weeks away and UNO seems to be finished and ready for release
are they waiting for the camera to release UNO ? that would suck