Eidos Montreal have released a brief video summary of Deus Ex: Human Revolution’s upcoming “Missing Link” DLC episode, with lead narrative designer, Mary DeMarle, serving as narrator. DeMarle says that Missing Link will give you about an additional five hours of playtime once it’s released:
Eidos also say that they’ve made technical tweaks to the game engine, allowing for better lighting in the Missing Link. The DLC is planned for release sometime in October. You can find more details of the episode here.