Going from Xbox 360 to PS3 takes "a lot of time and money", said Guillemot, so they're tackling PC which is then "translated into a console" like the PlayStation 4.
This is great news for PC gamers as we know we aren't the ones getting the port, necessarily. Ubisoft has also confirmed Watch Dogs is running on its own new engine;.
"Previously, we developed first games on the Xbox 360 and which were then translated into the PS3. It took a lot of time and money to make that port," CEO Yves Guillemot told Dutch site Inside Gamer. "Now we develop from the PC and which versions are translated into a console like the PlayStation 4."
On Watch Dogs: "At the moment our team is working hard to release the next generation consoles and the PC. Then other teams see how they can bring to the current generation of consoles. Maybe we at E3 two different versions can show."
Guillemot also affirmed the publisher's support of PlayStation Vita. "We are still a number of Vita games busy. I can not announce anything, but it's coming. The Vita is not dead for us," he added.
Watch Dogs releases on Xbox 360, PS3, PS4 and PC later this year.