I do not think Rosalind is red john but she must be an accomplice.
Jane is not red john, this is because he could not have poisoined the secretery, the secretery showed no love towards patrick, why would red johns accomplice(police men) try and kill jane if he was red john, jane loves his wife and kids, red john talks to jane via computer, after jane goes to mexico and finds the dead man and the prostitute a man most likely red john calls him and laughs in an evil manner to taught jane. there are so many more that i can't think of right now.
I think red john is a charachter we have only seen once and has been mainly in the background. I really hope it is not minelli because that is what everyone believes and it would be quite boring if they revealed it was him I must admit.
I can't wait to see who it is!
