The Teen Wolf panel at New York Comic-Con was today and we got a lot of spoilers from it! I have compiled a list of them below.
Jeff Davis said the door will be left open for Jackson to return if Colton wants to come back. He also said that there will be no relationship between Stiles and Lydia, just friendship.
Davis also said that "women will be finding their power" in season three.
There was a lot of interesting stuff revealed about the Alpha pack - There will be a female one named Kali who is barefoot and has claws on her feet. The pack will also be five large, which includes the identical twin alphas.
Tyler Posey said that "Isaac is going to thrust me with his greatness". There's also going to be a bromance triangle between Scott, Stiles, and Isaac.
Stiles is supposed to get a big arc during season three, starting in the second episode. The fact that Stiles is bisexual is "entering into spoiler territory."
Allison will have a redemption arc in season three and want to join Scott's pack.
Stiles/Derek could happen, but Jeff wants to wait and see how it goes.
So, it seems like there's a lot set up for the storyline next season. Stiles's bisexuality seems like it's going to be covered, too, and Derek is reportedly have a relationship with a female Alpha. Maybe Stiles will get together with the new gay character?