I feel like this is too clean cut to be a definite leak (tech companies have a habit of making faking their own leaks), plus Microsoft hasn't taken this down yet, but I'm not complaining and it's always nice to see the system software of upcoming consoles in action.

Honestly I feel that the system software is all there is to look forward to when it comes to any next gen console announcement as the games come out on everything anyways (Example: People play Xbox for Xbox Live not Call of Duty which you can get on PlayStation and Steam anyways).

(Source: The Verge)