Just found this on the HMV website. Not sure if available for the same price in-store. Nearest price is Bang CD for £7.99.
The chicken strikes back as [adult swim] travels once again to a galaxy far, far away to release the second, all-new Star Wars-themed special of Robot Chicken that includes a special extended edition with 15 minutes of brand-new footage and over 90 minutes of special features. Creators Seth Green and Matthew Senreich, Robot Chicken: Star Wars Episode II transform the galaxy into the stop-motion animation world that is the hallmark of Robot Chicken.