The main draw to Bioshock in general is most definitely its atmosphere and single player uneasiness as you traverse the weirdness that is Rapture. Unfortunately once you make it to the end of the game in principle that's it. Turn off the lights, the adventure is over in classic terms, but not with the new era of Downloadbable Content.
Announced today to be released for the Xbox 360, PS3, and PC -- Minerva's Den is to add on substantial single player content where you aren't a Big Daddy, but a mere "normal" human as you align with Tenenbaum "to unravel a dictator’s stranglehold on a key district in the distinctive city under the sea."
“Minerva’s Den is a substantial addition that will give players more of what they’re looking for: more story, more narrative, more gameplay and more of Rapture,” said Christoph Hartmann, president of 2K. “The core team has created an exciting product that further enhances the mystery and allure of the world of Rapture. Minerva’s Den will be a fitting conclusion to the BioShock 2 saga.”
Minerva's Den is to be released sometime in fall 2010.