Yeah, this seems like it could be a big deal. Not going to impact console games, obviously, but considering Steam's market share this could be massive (especially for Dota). Is it being monetized at all yet, anyone know? Or is it just another incentive to develop for Steam?
No monetized. But it's still only in beta (need to download the Steam Beta client), so who knows what the future holds.
I just tried with a friend (so only person watching).
System: i7 920 @ 3.5 Ghz, 4 cores + Hyper-threading on, 6 MBit/s upstream available
Stream settings: 1920 x 1080 resolution, 3500 kb/s max bandwith
Actual bandwidth use topped out at 2800 kb/s. CPU utilization was surprisingly modest. It went from ~20% game-only to ~50% when streaming, evenly distributed over all 8 cores.
I'd be curious if the streaming runs via a server or is peer-to-peer, ie. do I need double the bandwidth if two people are watching? (Don't think, so but who knows?)
I can see this taking of. Usage was absolutely uncomplicated. Friend right-clicked my name in Steam, selects "Watch Game". I got a popup asking 'allow yes/no'. And that was it.
I'd be a bit careful with the setting "Anyone can watch my games", especially if combined with the option "Record my desktop when not in game".
Overall a really nifty addition.