Last time I talked about Watch_Dogs I was worried as it is being published by UBISoft. In the past UBISoft have treated PC users are criminals with retarded always on DRM.
Since Farcry 3 I have seen that they have backed away from this and generally go the extra mile for PC users ( loads of graphics options and patches that enhance gameplay ).
Assassins Creed 3 was also very good on the PC.
The reason for the PC being lead platform is that the PS4 is basically a PC in a box.