Apparently Enslaved: Odyssey to the West was too much of a game to fit all of the main characters in on go. So, Pigsy is coming via DLC. And it's "Premium" DLC. That is, of course, code for 'pay for it". According to
Joystiq, "The publisher offers few additional tidbits about the premium add-on, noting simply that it will be a side story requiring the retail game to play. More details are expected in "the coming months."
We expect to see Sandy and magic, flying cloud DLC as well then.