Trine 3 is in development for PC, Frozenbyte Games announced this morning. You can watch a trailer for the game above.
Trine 3 will once again allow you to play as the Thief, Wizard, and Knight. Details on the game are scarce at the moment, but Frozenbyte plan to release it sometime in 2015.
You can find a few screenshots of Trine 3 below.