2K has just announced that the first major DLC for BioShock Infinite, Burial at Sea: Episode 1, will be available on November 12th for $14.99 (or included with your Season Pass). This date is a worldwide release for the PS3, 360, and PC, so no timed exclusive or staggered release nonsense here -- everyone is getting it at the exact same time.
Burial at Sea features a self described "film-noir" themed story as you explore the original BioShock's Rapture setting, and encounter some "old friends." I have no idea what to expect from it, but rest assured I'll be trying it out at launch with the rest of you. I'm just glad it's happening right before the massive double-console launch.