Those who wanted before the season 6 the end of RJ storyline and Jisbon stuff ,Are you happy right now ? You killed the series... 
I have to say that the half of the series is based on the complex and mysterious personnality of RJ  and with the way it ended it gained all people's disappointment.

I'm back... and so is Red John.
What I read here about 7x11 intrigued me enough to watch this episode. A note to all of those Red John fans who were/are disappointed by it's previous execution- You can safely watch this one. I can't tell if the remaining episodes will be worth your time, but jumping from 6x08 directly to 7x11 will make you feel like old times.

The clues and subliminal messages were dispensed one after another, and in a very good fashion. Even if they screw up the 2 episodes left you can make up your own theory about Red John, from here. And that is the benchmark for the good Mentalist show.
If you haven't seen it yet, don't read any further, as my theory will have some spoilers, but come back if/when you watched it. (Although, I might be the only one here who dismissed the whole 7th season.)

Anyway, here are my thoughts.

Gabriel,
Boy, do I like this name. Did you know that the Bible only named 3 angels? Gabriel, Michael, and Lucifer (or better known as Satan) I'm sure you noticed the #3, there, and only one of them was a real piece of work.

So what does this mean? Will Jane be only happy after he kills the 3rd Red John?
"You'll know when you see it" - said Gabriel.
Going by this info, here is my theory. Lazarus is the serial killer, but he is not Red John. Red John killed Gabriel, Lazarus killed the other victims in this season.

Why would Red John return?
Because Gabriel was a real psychic and Red John knows he was talking to Jane. He knows his secret is out, even if Jane is keeping it to himself. "FAKE" on the arm was a message from Red John to Jane. It obviously means more to Jane than it means to the others.

"You'll Know when you See it"
Clue: one of the old suspects are back. Jane will catch a glance and recognize him (perhaps in the crowed at his wedding) and hell will brake loose. However, I think 3 has a different significance not referring to Red John aliases. Jane will not be happy killing Red John. Every time he does that, it brings back the memory of his loved ones, murdered by the serial killer. Relief... maybe, but definitely not happiness. What I think it means, that Lisbon will die. Jane's marriage to his first wife, didn't end well, neither will his second marriage... I'm sure you know where I'm going with this.

As you can see, I'm happy with this episode, still I'll check out this site before I'll decide to watch the last 2. Then, even if it ends like crap, I can pretend, it played out according to my theory.

So i know imdb lies a lot but i just saw that Cbi Ron is in the final episode.
Asnwer most likely...he is invited to Jane and Lisbons wedding.

After watching the season final previews and seeing the house Jane wants to buy for him and Lisbon it just occured to me how badly this show is trying to force its two leads romance on us.  I stumbled across a FAN's  video of the Xfiles after the last movie was made and realised that even the fans are better at producing a worthwhile montage of a decade long relationship than Heller and Co. 
Sorry, I know most of you can't stand touchy-feely stuff but this video just proves that The Mentalist really could have done MUCH better.  Hat's off to this video-maker and the 10 years that Duchovny and Anderson NEVER ONCE acted like siblings.  http://youtu.be/TEJ4XdrqYbA

Number 3 means that the THIRD Red Joh killed by Jane will be the Real.