BioShock Locked Content Discovered, DLC Planned?

GamerNode brings us notice of a BioShock PC gamer having identified unused plasmids in the .ini files of the game. The Manual.ini file includes ";Downloadable content announcement" and "ManualTopicName=PlasmidPack1." This seems to hint at a future release of downloadable content.

If you're curious what the plasmids are, prepare to be spoiled: Machine Buster, Vending Expert, Sonic Boom, and EVE Saver. Sonic Boom is listed as being able to "hurl creatures and objects back with a blast of force."