The Captain Scarlett DLC for Borderlands 2 was already revealed due to a leak from earlier this week, but now Gearbox has gone ahead and officially announced the DLC, as well as a release date.
Set to come out next Tuesday, Captain Scarlett & Her Pirate’s Booty will be the first campaign add-on for Borderlands 2; meaning that it’s covered by the Season Pass ($29.99/2400 MS Points) for the game, if you bought it. Otherwise, it’ll cost you $9.99/800 MS Points. The announcement doesn’t go into what the add-on will actually contain, but you can always check out the leaked info yourself.
Between the Mechromancer being released a week early, and this add-on due to release next week, I think Gearbox Software is off to a good start on the DLC front.