Tried out the built in Shield TV twitch streaming. You can record, screenshot and broadcast, along with video and audio. I hooked up a Logitech webcam and it worked well. See examples in shots below. And here is the link to the actual twitch broadcast of Dirt 3 gameplay via Nvidia Grid streaming. The Twitch stream shows shots of the interface. Pretty sweet.

Imgur album (the second pic shows the video from the webcam): http://imgur.com/a/WkmkR

Twitch link: http://www.twitch.tv/russellwestbrookface/b/664340384

Edits: spelling & wrong game name. thx