You want legitimacy for game streaming? This is legitimacy. It's not a perfect solution, by any means--I have serious misgivings about YouTube's spotty record with copyright issues, and the possibility of needing a Google+ account to use Twitch. Jumping straight to #RIPTwitch is an overreaction, though, and a foolish one at that.
If Google or another interested party didn't step in, Twitch would likely be killed off in time, no matter how popular it is with the Dota 2 crowd. It would just die the slow, screaming death of a service whose back is breaking under the weight of its own popularity before another service with more funding and more robust infrastructure--you know, one like YouTube--came along to put an end to its existence.
Sign up for Computerworld eNewsletters.