The information surfaced over at the GameSpot Forums, and was backed up by blurry pictures of the article. The posters there and at NeoGAF also a provided wealth of other not-yet-verified details, apparently coming from the same source as the pictures.
Those unconfirmed details are listed below. Shacknews can confirm the validity of the above information, but can't yet say the same for any of the following points:
* The game is set 10 years after the first BioShock.
* There will be a multiplayer mode, but no details were given.
* The Big Sister is a grown-up Little Sister, and she's hunting you.
* Some levels take place on the sea floor outside of Rapture.
* The Big Sister will periodically pop up after you kill enough Big Daddies. Her arrival is apparently signaled by a Little Sister singing a song.
* The Big Sister is described as fast and "the hardest thing in the game." She'll utilize telekinesis to throw objects at you or use them as shields.
* Your drill overheats, and cannot be used constantly.
* As a Big Daddy, you'll be able to do that nifty shoulder bash move.
* Upgrade trees are now more diverse.
* The Incinerate plasmid allows you to throw a fireball or shoot a stream of fire, depending on upgrades.
* Using Incinerate on a Cyclone Trap will result in a flaming trap.
* You can now heal damaged turrets and bots.
* The game will reveal how Adam is recovered from Little Sisters.