As for gameplay possibilities, it would make certain games, like MOBAs or RTSs, that much more accessible on console. Granted, propping up a keyboard and mouse on your lap while on the couch is seldom elegant.
But Microsoft CEO Satya Nadella has been trying to make Windows much moreubiquitous across all platforms. That would mean that software developed on one platform will work on other platforms as well. Maybe the Xbox One could become a desktop alternative for many users looking for an affordable, powerful, PC.
If Microsoft were to go down this route, then it would definitely be a clear point of differentiation compared to Sony’s PlayStation 4. And in a market in which PS4 sales are dominating, it may do the trick to sway consumers.