[Update:] The video has since been removed.
Someone with a copy of Ryse and, apparently, an Xbox One or hardware strong enough to run that game, released this video yesterday, showing less about the game and the new console and more about how the dashboard performs on it. Awesome. The Xbox One dashboard. That really moves the needle on my enthusiasm.
Of course there is no gameplay. I've been here five years, and I know that there never is gameplay for this sort of thing. So this amounts to just another hit-and-run demonstration of features you don't give a damn about. Thank you, monotone narrator. Thanks for that namecheck of Bing. Way to sell this thing as not an authorised leak for Microsoft.
The account holder has published two videos and made two comments in his eight months on YouTube, which may or may not be relevant to your evaluation of this video's credibility.
I've sent an email to a Microsoft representative on a weekend (entire message body: "Is this real? OSG,") so I can get, by tomorrow, when you've forgotten about this, the obligatory no-comment reply. Meantime speculate all you like as to what this actually reveals, which is zero.
Xbox One Dashboard Leak -- Version 2 [NeoGaf]