CellaWeRRa's stream @ PC Bang and Sen's ustream channel are quite good even though they are across the world!
Seeing that free user streams have higher quality than several paid to pay streams, I believe organizers such as ESL and GOM can possibly learn a lot/work with ustream to provide higher quality HQ streams!
Given the popularity of streams and development of esports. I wonder if Blizzard would invest in adding live-broadcast and commentary technology into SC2?
Replays already track camera movements - how difficult is it to incorporate sound data and perhaps some simple text/mark data into the same file?
Instead of streaming video, Blizzard has the option to develop something which stream game data along with voice and camera movements. If streaming of a high quality video is possible, I don't see how the streaming so such data (which takes a lot less bandwidth) would be that "difficult".
Given the negative "make more money" image of Activision Blizzard, this is unlikely to happen. After all, they do not even have the time to implement chatrooms even though they delayed the game for a year for Bnet2.0...