I was just watching Episode 2 again...During the scene with Walt and John, where they are playing Backgammon, John was talking about the history of the game...He said
Two players, two sides....One is light...One is dark.
It just struck me as interesting. It was almost as if he were talking about something that we have to yet find out....Especially considering it is coming from John, he seems to be aware of what path he is taking, and he doesn't seem as though he would be the type to take the dark path....