According to industry rumormongerer Borderlands 2 downloadable content work to external developers. This is hardly new, as the studio did so with the original Borderlands., Gearbox will be outsourcing some of the
One external company named is The Workshop, which developed Sorcery for the PlayStation 3.
Some details in the rumor state that one of the expansions will feature over 10 hours of gameplay and is currently named "Torque", which just so happens to be the name of one of the weapon companies in the game.
The DLC will also cost $10 USD each, though a Season Pass is available to get all of the DLC under one price.