The only other game I've seen with this is the free to play MMOFPS Planetside 2. This page shows an example of their implementation with twitch.tv and I believe they have youTube support as well.
Tribes has it now. In theory, it shouldn't be hard to have a HTML5 video element added to the already most-HTML UI. That said, I don't see why we'd want live streams while playing... it'd get in the damn way!
livestreaming while observing would make a lot of sense though. but there is a lot of software for that by now, and I dont think Uber should focus on such things^^
