Answer:
There is a chance that Toy Story 3 is the last full-length movie in the series, but there appears to be no confirmation of this. However, it is confirmed that the Toy Story concept will continue to appear in the future. The director of Toy Story 3, Lee Unkrich, confirmed that there will be a short film that features several Toy Story characters attached to the Cars 2 movie, which is set to release on June 24, 2011.