(*Spoilers*) The most nagging unanswered question.
What possible sequence of events could have led to Booker becoming Comstock!? Did I miss a voxophone somewhere? I'm pretty obsessive about hunting them all down. I'm making the assumption that all the Bookers go through a similar ordeal as what we experience during the game, which would make that future something I'd want to stay far *far* away from. It also makes my brain hurt that Booker essentially sold his daughter to himself. Maybe I'm just not getting all this quantum multiverse causal timeloop stuff!?
I remember reading in an interview that enough content was cut "To make 5 or 6 games" I hope we see alot of it return in the DLC and fill in the missing peices. For the record I still loved the game and think it's deserving of all the praise the reviewers are giving it. However, I'm also not as angry about the ME3 ending now that I've had a few months to cool off :P
Booker was haunted by the atrocities he committed at Wounded Knee. Shortly after the war, he attempts to undergo a baptism to forgive himself of his wrongdoings. At the baptism, the infinite universes are created (because time travel) through the decision he needs to make. If he decides that a baptism won't make up for his sins, he remains Booker and has a baby who is stolen by Comstock. If Booker goes through with the ritual, then he becomes Comstocks and creates a tear to steal Elizabeth.