Ive had a chance to play the both versions today on my lunch and it most definitely is not 60fps constant on the PS4. Its smoother than infamous as the above poster mentioned. Its more akin to the fluctuations in Tomb Raider on the PS4 to be honest. Is 60fps for maybe 80% of the time. Oddly, the frame rate drops are not in areas where more is going on which is quite weird.
The Xbox one version doesn't look as good as the PS4 version. Cant really tell about the resolution. I'd guess though that 900p is a closer estimate. What is for certain however is the framerate is lower. Seems to be locked to 30fps. In fairness, it doesn't look bad because of it. In fact, because it seems to be totally constant, its less jarring.
But it is a cracking game though in the half hour or so I got to play.
PREDICTIONS FOR END OF 2015: (Made Jan 1st 2015)
PS4 - 34M - XB1 - 21m - WII U -12M