In what will probably come a surprise to no one, given the franchise’s success, 20th Century Fox has greenlit a third Alvin and the Chipmunks movie, Slash Film is reporting. Perhaps also unsurprising is the studio’s decision to produce the movie in 3D. Opening just one week before Steven Speilberg’s own 3D film, The Adventures of Tintin, Alvin and the Chipmunks 3D is currently set for release on December 16, 2011.