I think it's safe to say Xbox One sales will never recover. Meaning that 2015 was it's peak year. I also think there's a pretty good chance that you'll see sales start to fall behind the 360 this year.
Bet with Adamblaziken:
I bet that on launch the Nintendo Switch will have no built in in-game voice chat. He bets that it will. The winner gets six months of avatar control over the other user.