First Impressions: Borderlands - Mad Moxxi's Underdome Riot

IGN has a first impressions piece posted that gives an overview of Gearbox's second DLC for Borderlands, "Mad Moxxi's Underdome Riot." From the sound of it, the gameplay is rather different from the core game and the first DLC. Primarily, you get a quest to survive waves of enemies that increase in difficulty. No experience is gained by killing them, nor do they drop loot. Honestly, it doesn't sound like a whole lot of fun to me... Shoot!
There's also a quest board in here, which initially has one assignment available called Prove Yourself. It's added to your quest log, and requires that you clear 5 rounds in three coliseums to get a quest reward. What's a coliseum? Well, each coliseum, of which I saw three, functions like Gears of War 2's Horde mode or Halo 3: ODST's Firefight. Each coliseum is separated from the main room by a load screen, and the first one is called Hell-burbia.
Jumping into this area kicks off with Moxxie -- a particularly energetic woman with fishnet stockings and a circus ringleader outfit -- screaming through a megaphone as slippery electronic beats pulse in the background. There's a crowd hollering as you're set in the middle of an arena that's built from pieces of the rest of the game world, from rusted metal houses to the lighted pumpkins of Jakobs Cove. Then the action kicks off.