This is a very simple theory about "Good Guys & Bad Guys". I've noticed that a few of the character(locke, juliet, ben) call other characters by their first names (James, John.ect). I don't know if this os some kind of sign, but it seems that a lot of the "good people" are first namers. But of course the first name occurance could always just be a sign of which group the survivers belong to. I.e: Others- Firstnamers, Cast aways: Nick names.
If this theory holds then James must be the the big bad guy in this entire saga, because he and first names don't mix.
That last was was a joke. Just incase you couldn't tell.