It was apparently top secret info, told in confidence to buyers at the Licencing International Expo 2009 (a Las Vegas trade fair where studios hawk their upcoming wares), but the news that a sequel to Monsters Inc. is in development at Pixar, alongside Cars 2 and Toy Story 3, could not be contained.
There are few other details as yet, aside from the fact of original director Pete Docter's involvement. Docter's Up is currently doing rather well on US screens, and we're intrigued to see what he can do with the same characters a few years on. After all, Pixar's only sequel to date was the utterly ace Toy Story 2, so there's a high bar there to vault over.
The same source also reports that Disney / Bruckheimer Western The Lone Ranger has now taken precedence over Pirates of the Caribbean 4, which has been bumped to summer 2012. Yo-ho Silver!