The Monsters, Inc. sequel has been renamed Monsters University and is actually planned as a prequel. Pixar is currently in development on the film being directed by Pete Docter and brings back Billy Crystal and John Goodman as Mike and Sully. At this time it's not clear if other actors from the original will return.
Monsters University marks Pixar's fourteenth feature, and follows "Mike and Sulley during their tenure at the University of Fear, where they start off as enemies and slowly become friends. It will effectively serve as a prequel to the events seen in Monsters, Inc." Currently there are few new details available on the film.
Walt Disney Pictures will release the film on November 2, 2012. I loved Monsters, Inc. and can't wait to see this Monsters University.