YouTube embraces Google+ Hangouts for live streaming
gigaom.com
gigaom.com
I will also say that YouTube have had a 'streams' feature in TestTube since 2007 which let you line up videos and chat and in a way was Turntable.fm or this feature in Google hangouts before either. They simply scrapped the rivalling YouTube product which failed to reach a level of success and replaced it with another Google tool which is more powerful.
For an example of the kind of interaction we allow for http://www.vokle.com/events/19937-its-going-down