Steam has launched it's Twitch competitor today, with the inspiring name of 'Steam broadcasting'. You can access all currently available broadcasts
from this link.
The two most popular broadcasts currently appear to be hijacked into playing anime and/or hentai (I didn't hang around long enough to tell). I think that little exploit will get nixed fairly soon.
Go check it out. Watching someone silently pretending to drive a train can be kinda mesmerising.