The generally believed rumour it that games are locked to consoles. If you want to play a game on a different console then you have to pay a charge to MS.
Kinect is compulsory on the One, whether you're going to use it or not. However it's much more accurate and apparently will work in smaller spaces.
The killer is no backward compatibility though. Plus the PS4 is faster (2.0Ghz vs 1.6Ghz, and DDR5 memory).