Ok, now that everybody is realizing that the leaked episode was fake (I explained it in at least 5 comments; someone else also integrated my proof), I'd like to come back to the main theme. Who's Red John.

"Brace (= couple ? "Fearful simmetry") or partridge" is a bit naive, but it really means that there are two RJ, one of them was Partridge. Or someone known to us by this name. 

I'm sure we will get some explanation, maybe not everything because the show had too
many writers and clues to give a thoroughly account, but we will also be disappointed by
the artificial craftiness of the plot.

Let's hope they don't ruin the ending too much. The fans have a way better vision of the show, of the clues than the writers, so I expect an avalanche of found faults after the real episod gets aired.