To be honest, I have no idea who RJ is. There are just too many hints and people involved.

In my opinion the storytelling is going very fast now. In the earlier seasons every once in a while there was an episode directly connected to RJ. I like the speed and intensity and how people showing off there real faces. But still, now it seems more focused towards the BA, which somehow is connected to RJ. Reed Smith seems to know a bit but can's explain it entirely.

I am sure there will be a big finale with something no one is expecting. It will leave us with new clues, more questions and a fresh start for the hunt of RJ next season. PJ will probably team up with someone even more unexpected. 
Heller is just too smart to reveal everything in the upcoming episodes. I kind of like that. 

Oh man, I love this show!

Hi Guys,
this is so much fun especially when you have a big report to do so you think ok I can not do this while red john is still unknown ;)

I remember that Bosco when on the death bed told Jane something then died, then when I saw the promo I recognized his voice, It could be (I still think Bosco is a good guy) that Bosco faked his death to help catching RJ, and then Jane and Bosco will meet in the church and Bosco says : game over, I won, I told you it is Bertram, but Jane disagrees.
I still think it is micheal Kirkland any way.

I know this is going to sound mental because he died years ago. But do you guys think Bosco could have faked his death somehow? :P
I listened to his voice all day yesterday and he literally HAS Red John's voice. Not just similar but 100% the same. 
I know it's crazy, I even made fun of people who thought it was him before..I apologize to them now.   

Reasons it could be him: 

-He loved Theresa so wouldn't hurt her
                                     
-He told PJ when he was dying that he will come back to haunt him (it could be like a sick joke)
                                     
-Surprise element because I'm quite sad that they let us see the sheriff in the promo, I can't believe they would do that..I will be furious if he is RJ and we found out from the promo a week before the Red John episode.

-Voice matches a 100%
-His secretary Rebecca seemed to love him, maybe they worked together.
-Lisbon had feelings for him in the past so he must have a side that makes him attractive to women.  

Reasons it can't be him:

-The doctors at the hospital probably wouldn't lie about his condition, he was dying
-Rebecca went to visit him with a gun so it really looked like she wanted to shoot him
-He has no hair and he is not thin

Anyway, it is probably not him and he is really dead. But at this point I would accept anyone else but the sheriff. They've really ruined it for me with the promo..:(