We didn't get to see the Xbox One's fantasy football feature, unfortunately, but Microsoft did drop a hint about it while we were there.
Apparently as part of Microsoft's partnership with the NFL your fantasy football players will update automatically during live games. The ESPN app on the Xbox One appears to be quite robust, and there's clearly going to be a lot of functionality there for football fans.
The full extent of that, as well as the rest of the Xbox One's capabilities, for now remains a mystery. But it's not going to stay that way much longer! Keep an eye out for our full Xbox One review in the coming weeks.