I've been reading thoeries in this forum for a long time and have never seen this one but first a couple of comments. I used to agreed most when reading these with the idea the Grace was RedJohn however that has obviously turned false but it was very interesting and I feel those with that origianlly theory were close. Number two... its a little unfortunate that the writers have the luxury of twisting and turning this until the last second and you know they are research our thoughts to see what would give the big surprise, which leads me to my personally theory..
Patrick Jane is Red John...  I think it would be fairly plausible for them to show that Jane is sufferrring form split personality disorder and doesn't even know it therefore he has been chasing himself all the while.. Red John is his alter ego and just as smart (cause they are they same person) but holds the upper hand cause Red John knows he is Jane but Jane does not hence Red John being a step ahead...
Like we all know, Jane is always three steps ahead of everyone and the mind is very powerful to show and hide things from the user...(like in the film Memento, where the dude looks for jis wife's killer and she never was actually dead)
This other theory is more far fetched however, but Brett Stiles i feel i connected somehow... I always felt he had the closest mind power to Jane and the always shared a secret perhaps the has never been revealed or that maybe only one knows about..(perhpas they grew up together or crossed paths in the carnie biz) so I do like the theories linking Stiles to this somehow i just don't know how he fits yet..
The whole Tiger Tiger thing I think is a ruse to add just another confusing element to this to be honest as the whole ball of wax is gaining speed barrelling down the hill to the finish...in short...

Patrick Jane will be revealed as Red John