It is quite possible you will either fight Daniel Cross, Vidic(using the apple), or something around TWCB. I think there will be more revelations in this game than in all the other games combined. They have a lot of questions to answer.
You just made my year. But, seriously Vidic will be killed by Desmond for revenge for kidnapping him and turning Lucy into a traitor. Vidic is the one Desmond will want more than anyone else. Rikkin will also have to die as well as that ***** from the MP story. Not sure if he will fight though I am positive surrounded by Abstergo security but Vidic will be the last to die.