So you ignored my entire post except for the word "Twitch"?
Almost all streaming services use an RTMP server of some kind. uStream, DailyMotion, YouTube, just to name a few, and the only RTMP player that has the desired features for these sites is currently Adobe Flash Player. The problem has absolutely nothing to do with streaming games, it has to do with the available infrastructure.
Like I said, support for custom encoders for local recording might get implemented, but you will not be able to stream with these, unless Adobe specifically implements support for them, or some other solution shows up.