At the time of this writing, you can't stream to Twitch using your XBox One, but you can watch it! The app is easy to install.
You can do it via voice: "Xbox, Bing" then say "Twitch" It should pop up. Install, and Pin it.
Or you can do it the manual way. Home -> Apps -> Search Apps -> Type Twitch
The quality was fair, it does crop off the edges of the picture. I was playing it as far away from my wireless router as I could get and the quality was good. I plan on using this for some of my late night stream watching. Just another way to watch Twitch in addition to my Roku and PC, of course.
Archaelund - Update 0.8.1 released
4 hours ago