However, once they patched up their differences the two projects were scraped but just recently concept art for the two sequels has surfaced.
Prepare for Monsters Inc 2: Lost In Scaradise (awful, awful title) and what could have been Toy Story 3.
Monsters Inc 2 first. The idea was for Mike and Sully to visit Boo on her birthday, however when they enter her door they find an old lady sleeping there. Turns out Boo has moved and Sully takes it upon himself to go look for her in the human world. Not too great or original eh? I really don't like the idea of the storyline and pretty please it got canned. Take a look at the below clips get an idea of what they were trying to do.
And onto Toy Story 3. As reviewed by this lovely site, Toy Story 3 got a maximum five star rating, one which we still fully stand by. Now the idea for the original Toy Story 3 was quite interesting, it involved Buzz being recalled back to the Taiwanese factory were he was made and the rest of the toys heading out to bring him back home. Sounds alot more interesting that the Monster Inc 2 idea and I think this could've worked. Some concept art below.
So there you go, two ideas that will never see the light of day. Interesting stuff.