When the service Mixer was cancelled, Xbox lost the built in streaming straight from the dashboard. This is something many people have missed, and now it's making a comeback with Twitch instead. The Xbox Engineering Lead, Eden Marie, revealed this on Twitter and also included images of what it looks like.
It is included under the Capture & Share tab, from which you can just select Live Streaming and your stream will start on your linked Twitch account (you don't need to download a Twitch app as it is integrated in the system). Initially, it will only be available for people in the Xbox Insiders program and Marie says it is "totally early days", but hopefully it won't take long until it is launched in a future update for Xbox.
<bild></bild>