SPOILER ALERT!
Some thoughts on last night's episode and the hunt for Red John.
Bob Kirkland hunting Red John himself was a plot point many of us saw coming and I was pleased with the way they did it.  I think Jane was pretty stupid to allow Kirkland to leave without telling him [Jane] anything as he would surely have expected Red John to have him killed. However we still don't know if Red John gave the order or whether Reede Smith was acting in the interests of the newly discovered "Tyger Tyger Conspiracy" which Kirkland was apparently investigating.
With regards to the Conspiracy it appears to cover most, if not all, aspects of California Law Enforcement and has members ranging from the FBI to the DOC (and also likely CBI and the Sheriff's Dept if we include Partridge, Bertram and McAllister in it as well)  The exchange between Smith and Bertram in 6x02 can now be taken as Smith's concern that Jane has information on the Conspiracy, likely due to the death of Brett Partridge.
In terms of a Red John connection to the conspiracy we can infer that Red John is likely a part of it, but the fact that he IS Red John is likely unknown to most of the others.  In fact Red John could have easily been one of the founding members.
Overall, I think that Ray Haffner is now (and for me he has been for  a while) the Prime Suspect in the hunt for Red John.  Looking at everything we have found out I can't see it being anybody else, apart from Thomas McAllister and I think it turning out to be him would be on a par with the old Murder Mystery cliche of "the butler did it" seeing as he appeared in one episode nearly SIX years ago and the writers had no way of knowing whether Xander Berkeley would even want to come back to the show.
Also; Much Props to Baki Kaan Sert for the discovery of the similarities between Red John's and Ray Haffner's walks, which to me simply adds more credence to Ray Haffner being Red John.  The GIFS showing this are here: http://i.imgflip.com/4a7bq.gif and http://i.imgflip.com/4a7e2.gif

First my english is not the best :/ sry for that..
My Therory:
in the episode 6x08 "Red John" we have a new actor !
look at this http://img5.fotos-hochladen.net/uploads/youngman8b3i47fdzl.jpg!
I think he will play red john at the farm in year 1988 ;O
look at him and his eyes he looks like the young Ray Haffner or maybe Mcallister but the sheriff have blue eyes not green.
What you think about that ;O ?

I just feel like Haffner is Red John, ti isn't michael kirkland and i know why bob was always asking, have you seen me because he has an identical twin so they look the same. 

down to 5 suspect, turned out the most obvious suspect, Agent Kirkland is just some Dexter kind of guy who had personal vendetta with Red John. So, here's my theory Agent Smith, Sheriff McAllister and Gale Bertram obviously a part of their 'secret powerful organization' but I think none of them were Red John, especially Agent Smith, cuz he killed Agent Kirkland in front a witness, Sheriff already proved that he didn't afraid of height and Gale is too close to CBI so I dont think he's Red John, which leave us with Agent Haffner and Visualize n cult leader Bret Stiles, but I'm gonna go with Haffner cause Bret is too old, he's probably the leader of the whole 'secret powerful organization' but Agent Haffner is the man who painted the red smiley aka Red John.

This episode gave a clear indication to me that the 'Tyger, Tyger' thing has implications beyond Red John, particularly for law enforcement in the state. Here is my theory on how it's all connected: 

Random quote - Stiles: "I know so much more than you or Red John can possibly imagine" 

Stiles is the head of the 'Tyger Tyger' group, making the most of Visualize's law enforcement contingent. Stiles and Visualize are obviously involved in shady business, even something as big as murder, and it's been implied several times. The followers are like drones, and many of them are law enforcement or connected to it. 

Red John is a member of Visualize. Ray Haffner. He has been utilising this 'Tyger, Tyger' group for his own needs. Recruiting followers, people in law enforcement etc. MAYBE even using the Visualize brainwashing techniques he no doubt will have seen or experienced as a member. 

Bret Stiles doesn't like Red John and his taking advantage of his empire. This along with his slight affection for Jane explains his leaking of some information down the years, however he clearly knows more. He holds most of it back to protect himself and the organisation. At the end of the day, the arrangement Stiles and RJ have is a mutually beneficial one. But maybe Stiles would like Jane to catch RJ to get him out of the way - but he has to go about it carefully, or risk exposing his own doings. 

Brett Partridge was a member, probably working on cleaning up or fixing crime scenes etc. Bertram is a member, one in a massive position of power. It also explains his randomly quoting Blake back in 'Red Queen'. Smith is a member (obviously) and so is Sheriff Tom McAllister. This explains the meeting of the three of them in Bertram's office, and also shows how it has corrupted law enforcement on different levels, from the head of the CBI down to a county Sheriff. Any of these 3 could be working for Red John through the group, or they could solely be a part of the 'Tyger, Tyger' group. That's a question that's still open. 

Why was Todd Johnson killing police? That's a question that has been asked many times. Could it be that he was simply getting rid of those in law enforcement who were catching on to the whole sordid arrangement? 

Finally, this was all hinted at back in season one. As we all know, Jared Renfrew wrote, in blood, 'He Is Man' or 'He Is Mar'. 

As it turns out, it almost certainly meant 'He Is Many', but in a way none of us expected. 

One thing I CAN'T figure out is the use of the poem. Did it exist as this 'password' BEFORE RJ quoted the poem to Jane? Said poem clearly has symbolic significance in regards to Jane and RJ, something that RJ surely knew whilst reciting it. But beyond that? 

I might have more to add to this as I process the episode and past ones. Cheers. 

Let me know what you think. 

I have been studying up on this for a while now. I think I've seen every episode of the show. And I'm pretty convinced, now more than ever, that Ray Haffner is Red John.

Here are my reasons:

First of all, Ray Haffner has been part of the show the longest (outside of Gale Bertram and Tom McAllister).

Second of all, he fits the description PERFECTLY. Better than anyone else. Rosalind Harker said that Red John was of average height, falling under 6 feet. He has an average build (not too soft, not too hard), and has short, straight hair. Sophie Miller said that he is middle aged. Patridge and Kirkland are both dead, so Red John can't be either of them. Bertram has very little hair, as does the Sheriff. Reede Smith is a little too "soft," and Bret Stiles is much too old. That leaves only RAY.

Third of all, every single one of the men call Lisbon by her last name. All but one. Ray Haffner calls her Teresa. And the way he says it is similar to how Red John says it. It sounds like "Treesuh". Remember, in the first episode of the season, "I'm sorry, Patrick, Treesuh can't come to the phone right now, can I take a message?" The very next episode, during Lisbon's dream, Ray calls her Treesuh as well. Also, kind of strange how Ray is the one to slit her throat in her dream, right?

Fourth of all (I'm sorry about the "of alls"), every time Red John has ever used an alias, he's always had 3 letters in his first name.
EXAMPLES:
Dr. Joe N.H.
Red John
Roy Tagliaferro (forgive the spelling on this one)
Jay Roth
RAY Haffner

Red John didn't kill Lisbon in the first episode? Why? The only reason I could think of is that he likes her. He even tried to pull her away from Jane last season by inviting her to join his private firm. He wants to hurt Jane, but killing Lisbon (which would devastate Jane) would hurt him as well. So he tries to do it by taking her away from him.

Ray is a part of Visualize. He talks, walks, and even resembles Red John. If it walks like a duck, and it quacks like a duck... it's probably a serial killer.

If it's not Ray, I'm going to be shocked outta my mind!

Love the show!

He's the only suspect left that fits Rosalind's description of Red John..