There has been a mass of rumors on the 2k marin’s forums, mostly all of them false. Buuuut, some useful and entertaining information also came from this. There is spoilers here, beware.
2k and Game Informer both said that the rumors concerning whether Big Daddy wouldn’t make a reappearance were false. Big Daddy’s are coming back, and they actually play a bigger role apparently. How, you ask? YOU will be the big daddy’s this time around. You’re one of the first Big Daddy’s and you’re on a search for your own little sister. You battle and target other Big Daddies with your arm drill and plasmid powers and whatever else is in your arsenal. You still have the choice to harvest them or adopt them as your own, the little sisters that is.
Your little sister side kick is going to be a useful addition, she can harvest ADAM from the dead bodies, and when Big Sisters are lurking by, she’ll act as a warning sign. This game sounds amazing already, Big Sisters have me quite interested. Supposedly feminine, amazonian-like, extremely fast and tall brutes. Sounds like a lot of fun, heh. Players have the ability to do all the things Big Daddy’s could do in the original, Bioshock, game. With the addition of character upgradeability and options. More information will be included in the Game Informer magazine soon to be distributed.