Netflix CPO Neil Hunt says that Sony has "promised" 4K support for the upcoming hardware revision and Forbes independently confirmed the Xbox One.
Says Forbes' John Archer, speaking of an elaboration on Hunt's blurb: "Namely that he believes that when both the PS4 and Xbox One consoles do their traditional two-year hardware refresh (which would be due around October or November) they will add the necessary components to deliver 4K video playback."
If accurate, the consoles would most likely have to see some particular hardware and software revisions. HDMI 1.4 ports would likely have to be upgraded to 2.0 (which allows for 4K at 60fps) and HDCP 2.2 protection would have to be included as well.