Most of the innovation is driven by the streamers and target viewers anyways. Just check out the events that people like Ibai are doing - bigger and more fun than anything Twitch has done.
I find it difficult (outside of adding more dev tools and allowing for things like twitch plays pokemon as someone mentioned earlier in this thread) that a corporate implementation of a new "thing" will be as successful, partly because of the vicious backlash against whatever corporate sanitation measures would have to be implemented just to allow it on the platform.
I think there's a fundamental disconnect in what is most fun and engaging about watching and commenting in chats on twitch and what twitch as a company would allow if they tried to invasively step in an manage the product.
A good example of this was a few years ago, there was almost universally panned attempt to create some form of "moderation council" which turned out to be absurdly tone deaf and I haven't heard anything since.