Oh yeah, it looks like YouTube is the answer to previous posts on Who Will Be The YouTube Of Live Video?
Live video on the web does matter but not in ways used right now. Here's a backgrounder on live video via NewTeeVee; at around time 1:50 (in the middle of the time bar), YouTube co-founder Steve Chen tells Pop17 videoblogger Sarah Meyers that YouTube is moving in:
Update: live from mobile devices is next up; see Live from your mobile. The next big thing? at Watching TV Online.