Take a look.
Borderlands 2: An Introduction by Sir Hammerlock trailer:
Join Sir Hammerlock on an introductory tour of Borderlands 2 as only he can present. Discover all of the new locations, characters, enemies and oh, yes, weapons and you prepare for your journey. The Borderlands are waiting.
Borderlands 2 is scheduled for a September 18th release for the PS3, Xbox 360 and PC.