If the bean-counters at 2K games think the game will make x% more money simply by having the BioShock name on it, it's going to have the name on it. You and I have the luxury of making an artistic decision, the publishers and developers less so.
I'm willing to bet they'll shoehorn in some characters related to the first BioShock games to keep continuity.
Someone made the joke that Columbia will fall into the see and become Rapture at the end of the game... and the big twist is that somehow the character you play is Andrew Ryan.
If it hasn't been answered yet, I think the another question is whether or not the game will have death match. Given Bioshock 2 had like 5 developers working on it, I figure they took a bath developing a multiplayer that no one played.
One thing the game needs to address is race, since the in game posters seem to indicate a "white only" society. Bioshock 2 tried to address this with one of the characters being black, but it was all "we were supposed to be equal but old prejudices never die" or some such. These Columbian people have to just be rampant racists. Bonus points if they make the main character/player character racist as well, just to make everyone uncomfortable with playing a hero who we would considered flawed.