It seems the PS3 version of BioShock was blessed with more than the extra features previously known of, as determined gamers found out upon completing the game. Backing out to the main menu reveals an unlocked teaser trailer for the sequel, now revealed to be titled BioShock 2: Sea of Dreams.
Very little is shown in the brief CG movie, which has been produced in the same style used for the X06 trailer and launch trailer for the original game. We see a little girl, presumably a Little Sister albeit apparently older than in the game, holding a small Big Daddy doll, looking out to sea. Behind her the sand shifts and undulates to rise up in towering shapes that form the buildings in the BioShock logo, which appears looking visibly worse for wear, with barnacles affixed to it. Not all is old and broken, however; a vibrant blue butterfly emerges and spreads its wings.