Update: apparently the information provided to Golem was not correct, as Ubisoft announced today that that "on new-gen systems the game will run at 900p on PS4 and 792p on Xbox One, at 30 frames-per-second on both consoles. "

Below you can read the original article:

A lot of talk has been done in the past few days about the frame rate and resolution of Watch_Dogs on PS4, especially due to this little mishap, but a new preview by the German site Golem could shed some light on the issue.

The preview mentions that Ubisoft told (probably during the preview event) that the game runs at 1080p and 60 frames per second, and the writer mentions that he (subjectively) noticed barely any frame rate drops while he played the game.

That said, this comes at a cost, as the build examined seems to have very weak ambient occlusion and visible aliasing. The weak ambient occlusion is especially noticeable at night, during which many objects seem to "float in the air" and several don't cast shadows. According the preview, textures are also slightly blurry and lack Anistropic Filtering, which is something we already saw in other multiplatform games.

The writer also mentions that this should be less of a problem on PC, that uses HBAO+ for Ambient Occlusion and and MSAA/TXAA (the latter only for Nvidia video cards) for anti-aliasing. 

Of course the mystery on why Sony removed the mention of 1080p and 60 FPS from the PlayStation website remains, but that could be explained in various ways: the most likely reason is that the frame rate isn't fully locked at 60 frames per second, so the house of PlayStation decided to play it safe instead of being blamed later for advertising a firm number that isn't always solid.

Of course that's just my personal speculation, so take it for what it's worth.