Latino Review has posted a rumor that is the inevitable byproduct of Disney/Lucasfilm synergy. According to their sources, Disney subsidiary Pixar "has been given their own Star Wars movie."
The site does not offer any more details about the film, and the sparseness of the rumor suggests that, if it is true, the project is in the early stages of development. With the recent success of the animated TV series Star Wars: The Clone Wars and the promise that Star Wars Rebels holds for the franchise, it's certainly easy to imagine Disney executives green-lighting another animated project.
As always, nothing is confirmed until Disney or Lucasfilm says it is, so take this rumor with a big ol' grain of salt.