It obviously can be used for that, but I think it also gives an avenue for those that are REALLY GOOD (or really bad...) showcase their skills in how they play the game, or just be a way for people to mess around...
I'm sure we'll see more opportunities and different uses as gamers find all sorts of different ways to use the streaming features... we'll see though...
Perhaps that too, streaming games is REALLY popular now. Some people enjoy watching others play while they do a commentary at the same time etc. I don't really know why, personally I rather play myself than watch others play, but obviously many like to watch other (probably better ones too?) players except them. Just go to twitch.tv frontpage and you can probably see how theres a HUGE amount of people streaming different games and many of them have thousands of watchers live.
I guess part of the reason is how it's live and many streamers interact with their watchers who can comment through the chat.
So not even an ETA? That sucks, because while I've never been one to use those sites, I'd considered hopping on and getting a look at the games that way when the console launched. Sucks.
ETA is "first part of 2014", but that could mean a lot of things. Could be Q1, could be first half..