According to the Ubisoft Blog, Watch Dogs will run 900p on PS4 and 792p on Xbox One, and both at 30 frames-per-second.
"Resolution is a number, just like framerate is a number," saod Creative Director Jonathan Morin. "All those numbers are valid aspects of making games, but you make choices about the experience you want to deliver.
"In our case, dynamism is everything. Exploration and expression are everything. You want to have a steady framerate, but you want to have dynamism at the core of the experience. The same goes with resolution.
"People tend to look at corridor shooters, for example, where there’s a corridor and all the effects are on and it’s unbelievable, and they forget that if you apply those same global effects to an open city with people around and potential car crashes and guys in multiplayer showing up without warning, the same effect is applied to a lot of dynamic elements that are happening in every frame.
"So it becomes magnified in cost.”
There's more information through the link, but hopefully this clears things up.
Watch Dogs arrives on May 27 on PC, PS3, PS4, Xbox 360 and Xbox One. The Wii U version recently went into full production.