I wrote this as a further development of what has been explained in #6549 and #6687. The main fact of this open field of theories (not all mine) is that the Tyger tyger organisation and RJ are not linked or the same.

The Tyger club is clearly linked to William's Blake poem.

Everything we thought Red John was referring to in that peom about his relationship with Jane, now appplies to the Tyger club. The symmetry stuff, is like the two "faces" of the law. This meaning a "clean" organisation that work as outlaws, a sort of vigilante web, OR an organisation that commits crimes to "justify" or to ensure there's a reason to have a CBI. Like a pyromaniac fireman.  Have it be a regular maffia would be just lame, so I'd go with one of those two.

It is a possibility that the Tyger club is against Red John, this would be why Red John would give that clue, that warn, to Patrick. Or maybe RJ needs the tygers down to do something. Or he just tries to distract Jane with another huge net of illegal business that isn't his.

Asuming that Betram, McAlister and Smith are in the Tyger club and by the reasons given in previous posts the ones in the club can't be RJ, I think Haffner is a pretty obvious choice. But we have to go beyond. We have to think not only who the most logic suspect is withing the show, but also, why, as a writer, would you have it be him. Reasons outside the story.

RJ is a smart character. You would want a smart character not to commit suicide just for fun. If RJ has given Jane so many clues about himself with no reason, he'd be plain stupid. But if RJ, the smart RJ is willing to give up his identity it must be because the next move after he is found has already been planned. If I was RJ, the only reason i'd give up my name to you, who want to kill me, would be because there's something greater at stake. Same reason why I would have sent you so many messages to be friends in the past.

Clearly, the Tyger club being discovered by Jane is as or more important to RJ that his personal cat mouse game with Jane. Maybe without knowing, after being killed, or after he's discovered, Jane will fulfill RJs "pure" goal which is to combat corruption within C.L.E. Let's remember he has gained so many adepts so the guy must look and sound like a good, transparent, good-intentioned person. Maybe that's the symmetry of William Blake.

So the writers say Haffner. Obvious. The viewers say obvious =  boring. Oh but no.

 Maybe RJ being Haffner is a basal point to further developments in the series. Perhaps (not perhaps, clearly) to discover Roys real name isn't Jane's merit, but RJ's last or greatest move. Ray John (from now on..) can easily have better arguments than the other suspects to f*ck Jane's upcoming life.

Why? Lisbon. Plain and simple. If you were a writer, would you loose the possibility, no matter how obvious it is, to have a triangle between the killer, the inocent girl and the smart guy?

So many chances, for instance:

Ray forces Jane to "use" Lisbon somehow, as a beacon, as a hostage, as a messenger or whatever. RJ sets a scruple test for Jane. His major goal (killing RJ) for his major chance of redemption in life (Teresa). Would Jane cross the line? I think he will, and John will be killed, but Lisbon will be definetely separated from Patrick. Therefore the Blue Heaven. You can't have the pie and the cake at the same time.

Maybe Ray finally seduces Lisbon (I don't think this one's probable, but it's another possible way to go), so not only jane's past, but also his future would have the RJ stamp.Maybe he even kills her or threatens to.

Or whatever else you can imagine as an interaction between John, Jane, and Lisbon as a trading coin or object, may definetely change the game and the relation between Patrick and Teresa from a human POV. It's not just kill her, there are other layers to be exploited.
And there would be a strong moral Dilemma for Patrick.

That's why it's important that Red John and Lisbon share an independent link, not Jane mediated. And the only character that currently has it would be Ray Haffner. If bad handled, it's a mexican soap opera. Well handled, I think it's the most interesting path to go if I was the writer of the show.

Keep a continuity element after red john is gone (the tyger club) and change the relationship between Jane and Lisbon BECAUSE of Red John, not just "red john is dead, let's be a couple". More like "you used me, you were willing to let me die" sort of think. In the end Jane is a sociopath just as red john. Or perhaps he doesn't dare crossing the line and RJ wins.

Again, so many possible emotional and character developments and gamechangers with Haffner being red John, obviousness and surprise are not the only important things and factors in TV to design a show. We are caring so much about who red john is, and not about what he will do with this de facto couple, that is Jisbon. And I bet he will wanna do a mess, and the better positioned to do that is RH.

Lost, in the end was 100% surprise, and no interesting development of the characters. Surprise is overrated and I really hope the Mentalist doesn't fall in that burse