Just one day after the PC release of the first Borderlands downloadable mini-expansion comes the official word for the next DLC release. Borderlands: Mad Moxxi's Underdome Riot will also be released for the PC but no date has been announced (the Xbox 360 version will be release on December 29 with the PS3 version due on January 7)

The DLC adds three new Riot Mode arenas to Gearbox Software's FPS-RPG hybrid. Players will have to fend off waves of the game's biggest foes. It also adds a new bank feature for more storage of items and lets characters have two more quest points for rewards.

[via email press release]