So, through reading the comments and stuff throughout the wiki, I keep coming across the people linking Juno saying "The cross darkens the horizon" to Daniel Cross from The Fall. Well, that got me thinking. If I remember right, Ubisoft said that the novel and its characters would factor into the games at some point.
Well, Daniel knows of an assassin named Bill Miles. Now, because of the name last name - the fact that two characters in a game with the last name are never unrelated - it is considered by many that Bill Miles is Desmond's father, who Vidic implied was dead but never actually stated. However, there is another possible link: William M., the man who Lucy and Shaun are both in contact with, and who tells Desmond, ironically, that the two can't be trusted at the end of TDVD. Since Bill is a nickname for William, and since Miles starts with "M", it is possible that the two are one and the same.
But my point is, we know that William M. is one of the two people who's talking during the Brotherhood credits. However, has anyone considered the possibility that Daniel Cross may be the other person? It sort of makes sense, and it is a way to introduce his character into the games.