My brain got hung up on Colombia attacking New York in 1984. Why? Why did this, seemly reformed/repentant Old Lady Elizabeth attack NY, then summon DeWitt to make things right, right at this moment? Did she have have a change of heart on the trip there? Or is attacking New York PART of her making amends?
Something I noticed in the game, and I'm sure plenty of others have too, is the anachronistic music in "1912" (
http://www.youtube.com/watch?v=MLr31ycZVtUcovers most of it) I think Fink and his brother Albert were both young and living in New York in 1984. The music in game is all stuff that the two brothers listened to in the era they grew up in/loved/whatever and brought with them, back to the past. Colombia/OldLadyElizabeth is trying to prevent Fink from using a time-tear thing, which he plans to use to go back, re-brand plasmoids from the fallen Rapture as Vigors, and use that money base to...I dunno, be an evil dick or whatever. I get the feeling the real key to Fink's plan is that Shock Jockey actually replaces electricity, with him being the only supplier. We got a peek at the successful version of his plan when Elizabeth and DeWitt go to the Colombia ruled by Fink. I think Songbird may be Fink's brother Albert, damaged severely in the attacks in 1984 from Colombia as run by OLE. Perhaps his guardianship of Elizabeth was multipurposed. By being in control of the books she read (she said Songbird was the one that brought all of them there), he could perhaps mold her into a person that would never attack New York. Failing that, if she never leaves the tower and/or never meets DeWitt, then the same goal is achieved, and hopefully Songbird/Albert isn't hurt and lives a normal life.
So the DLC (im guessing two installments) would be focusing on the different two other worlds we saw in the game. One where Fink rules, and perhaps you're DeWitt, or maybe you're the brother, I dunno. The other world would be Daisy's/Vox run world. The only curious point about that one is; how did Comstock exist in that world if DeWitt martyred himself to stop him? No clue.