As what last week's leak might've told you, Borderlands' fourth DLC pack does involve a Claptrap and a revolution. Gearbox Software has announced the details regarding the aforementioned add-on, and yes, it's all true. In fact, the DLC is called "Claptrap's New Robot Revolution."
You'll find yourself caught between Hyperion's armada and an uprising of Claptraps led by the kung-fu expert Ninja Assassin. You'll have to work with Hyperion to subdue the Claptraps, so you'll also have to set aside the fact that you're not fans of each other.
No date has been given, but the DLC will be priced at 800 Microsoft Points, US$ 9.99, or £6.29 depending on your system and location.