Much to the dismay of practically everyone, rumours that the Xbox One would require a constant internet connection—and a good one, at that—had been running rampant. You can officially put those fears to rest, for the most part. Even though there was no official statement today, by all accounts, the Xbox One has the potential to be totally as enjoyable even when you're offline—as long as the game developer is willing to play nice, that is.
According to Wired, Xbox One will be giving developers the option of making games that rely on Microsoft's Azure cloud service. Should they choose to do this, the game would be able to run partially on the cloud instead of bogging down your machine. This would also then mean you would only be able to play the game with a constant internet connection.
So presumably, single player games not running on Azure, Blu-ray, and live TV will be just as accessible to those with a lacking and/or unreliable connection as those speeding along on broadband.
Microsoft certainly seems to want to eventually make the move to an "always on" Xbox, though, since they'd be able to crack down on piracy and generally enforce stricter security. Effectively barring a still significant number of Xbox enthusiasts in the process.
An earlier report by Ars Technica cited an internal Microsoft email claiming that multiple features would "just work," even without a connection. But as of now, it seems like those features are more limited than we might have hoped.
Still, any hopeful Xbox One owners looking to occasionally disconnect can, finally, rest easy—mostly.