Apparently it's still 1080p60. While the car models and shading look fantastic, the environments in Project Cars are usually pretty inconsistent even on the PC.
Still, if Project CARs can do 1080p60, I wonder what DriveClub is doing that it can't. My guess is the environments are far more detailed in DriveClub.
Also if you look at these things in their full size you can see some jaggied edges and whatnot, stuff that I usually don't see in PC screens. These came from the Playstation Blog on the Playstation Blog's Flickr account and the post was made by the Creative Director of the game. No reason to believe these aren't PS4 pictures.