This feature and the secret November 27, 2013 film will give shape to Pixar's post-Brave slate, which is likely to be announced at the D23 Expo in Anaheim next week.
It's been confirmed that the 11/27/13 project will have an original (i.e. non-sequel) story, but the same hasn't been said about 05/30/14.
Could it be Toy Story 4? Please share your theories in comments.