Gfest finds trailer mashups to generally be dissapointing. This one, which mixes footage of Toy Story 2 with the audio of the trailer for THE DARK KNIGHT, is extremelly well done.
Where this one succeeds is in the "casting" department. Woody is the Joker, Buzz Lightyear is Batman, and T-Rex is Alfred. It will all just seems so natural once you watch it below.