I perform 12-15 gigs a week in SL and other worlds using a live video stream for most of those gigs. I use a Quicktime video relay stream to feed live video to the audience. I've been incorporating video as a part of my shows for well over a year. using a MacBook Pro iSight webcam, streaming H.264 video and audio. I use different lighting setups (colored lights, lava lamps, RL facelights!) and my avatar 'plays' custom guitars that look like my real guitars the listeners have the choice of listening to the music OR watching video on the media stream with syncronized audio, i feed a separate audio stream if listeners have issues with quicktime video. other musicians are doing this too. Craiglyons Writer and The Follow also have been known to use live video.