The latest Borderlands 2 patch for PlayStation 3 appears to have outed our first details of the game's upcoming second DLC expansion pack, according to a poster on NeoGAF. 2K Games has yet to reveal what will come after this week's Captain Scarlett and Her Pirate's Booty add-on pack, though we know based on Season Pass plans that Gearbox Software intends to release a total of four add-ons between the game's September 2012 launch and June 2013.
It looks like the title for DLC2 is Mr. Torgue's Campaign of Carnage. There are three PS3 Trophies connected to it and they're all pretty similar to the Achievement/Trophy rewards attached to Captain Scarlett. One Trophy unlocks for completing the "Long Way to the Top" mission (presumably the last in the add-on pack's story), one is awarded for completing all Campaign of Carnage side missions, and one goes to players who manage to find 10 collectible pictures of Moxxi in the DLC.
None of this is officially confirmed of course, but the info certainly suggests that it's possible we'll see a second Borderlands 2 expansion before the end of 2012.