Left 4 Dead DLC Will Include More Levels, Enemies; Xbox 360 Version Uses Dedicated Servers
The company plans to add new scenarios to the game's initial 4, as well as new bosses and weapons. "There were strong hints at a flamethrower coming not long after launch," 1UP reported after talking to Faliszek.
The Valve writer also promised that the studio aims to make that DLC available more quickly than they have done with Team Fortress 2. It is unknown whether that content will be free on Xbox 360, as Valve's penchant for free content on its PC games has met with resistance from Microsoft when releasing new content on Xbox Live Marketplace.
For the Xbox 360 version, Valve plans to offer dedicated servers ... Read more

Zombies: Love or hate them, they're an inseparable part of pop culture, and an inevitable part of many apocalii. One way this phenomenon is manifesting itself is Valve's co-op shooter Left 4 Dead, coming in November for PC and Xbox 360.