I believe that we've known who Red John is for quite some time now. I think that Jane has a very strong theory that he doesn't want to believe...I say this because whoever Red John is could very well be someone from Jane's past, Perhaps his Father? Jane's Father encouraged Jane do trick people while they were apart of the Circus, although Jane did not feel comfortable doing so with the tricks of physic powers. But, Jane ends up doing that very thing for a living, fooling and tricking people for a financial gain, I believe that Jane's Father was upset about this and saw Jane as a Hypocrite. Jane's Father has sought out to teach his son a lesson. At first I thought Jane was Red John, how Epic would that be, huh? Jane himself sets up all these Murders and has accomplishes that only very few know who he really is. Perhaps Jane is a psychopath and will ultimately lead the CBI team directly to him and have them not believing what they see or what all the evidence is pointing to. BUT, that is just a wild theory that I had in the very beginning, LOL! I really think it's Jane's Father and the Finale of Season 5 taking Jane back to his past really makes me think its Jane's Father, who else would know about Jane's childhood secret and use it to hurt him?