Pixar just uploaded a sneak peak from the latest Toy Story Toon, Partysaurus Rex, which will play before Finding Nemo 3D (released 14th September, US; 29th March, 2013, UK). UPDATE - Pixar've made the clip private, fortunately Stitch Kingdom have uploaded it, in HD, above.
The short is being described as "a Toy Story rave", and sees everybody's favourite neurotic dinosaur trying to reinvent himself at Bonnie's house. It turns out having arms makes a toy very in-demand at bath time! Check out the clip (above), which is certainly a bit different for Pixar, but - as with previous Toy Story Toons - is very funny.
Partysaurus Rex is directed by Pixar veteran Mark Walsh, over at Pixar Canada, and the music was created by techno-artist BT. Also, check out Rex's King Fergus look above - surely one of the many Pixar references we've been told the short features.