Wait isnt this the thing that people were reporting like 2 weeks ago was about to be rolled out?, wtf.
Xbox tweeted it was an old prototype at that time.
People were just guessing that there was a new prototype (myself included), apparently there is not. Might be in their best interest to see if they can get the app supported on Roku devices (would require at least BT for a controller, not sure if Roku has that) and Fire Sticks (would be competing with Amazon's own service, but Amazon competes with Netflix and Hulu on its devices as well). If you can do that along with smart TVs, it basically just comes down to letting people know the feature is available.