The new Xbox is online always (you must sign in once every 24 hours for it to stay active), you cannot play used games without a fee so all rentals for that system are now useless, it will be pay to play, no self publishing for indie developers, Kinect is required for the system itself to function, etc.
There's literally 0 reason for me to buy the Xbox One, the Wii U PS4 and PC will have all the games I need without having to deal with a complete trash of a system.
edit - this is coming from someone who owns a 360 and has played most of the exclusives on it and generally enjoy the system, not biased in any way, the console just screams awful from what has been announced for it.
“Anna, my strong, terrifying Anna.” -Cas
"You lack the requisite spine and testicular fortitude to study under me" -Elodin