According to John Lasseter's Reaction Pixar is Developing TOY STORY 4
Last month Tom Hanks let a little news slip that Pixar was working on developing a Toy Story 4 even though the third film was supposed to be the last in the feature film franchise. If Hanks says something like that you know that there's got to be some truth to it. Pixar director John Lasseter recently popped up on a UK morning talk show to discuss Cars 2. During the interview he was asked about what Hanks said about Toy Story 4, and he neither confirms or denies it, he just says they haven't officially announced anything it.
So basically Toy Story 4 is currently in pre-development, and are most likely in the process of cracking a story. It's kind of funny watch Lasseter squirm when he's asked that question. His whole body language says, "Yes! We are working on Toy Story 4!, Damn you Tom!" He completely gave away his hand, Lasseter would be great to play poker with.
I thought Toy Story 3 was a perfect ending to the franchise, and I honestly don't see the need to make another Toy Story film. It takes all the emotion out of three being the last movie in the franchise. Check out the video interview below and tell us what you think!