I expect PS4 to be much inferior. Stereoscopic depth perception is highly demanding image processing, needing image recognition algorithms. These will be sensitive to light. Better results can be obtained by throwing more processing time at the problem, but I expect the results in a realtime console to be rather coarse. The tiny details of Kinect 2 are definitely out of the question. Tracking a fist moving towards the screen against similarly coloured background would prove incredibly taxing. Use of props would help, so wearing boxing gloves, their speed could be detected similar to Move orb tracking.
I suppose there's risk that Kinect 2's feature use in games will be somewhat capped to PS4's due to developers targeting lowest common denominators.