I was thinking about who Red John is for a while now. I didnt believe it was Jane, I always suspected Cho i dont know why but to me he looks identicly like the Red John's smiley face, until today i watched the Red John's rules episode. 

I guess many of you havent noticed what the song in the end of the episode is about. :) http://www.youtube.com/watch?v=7Cxhl8AwOf0

Something's got a hold of my heart!!!!!!
Keeping my soul and senses apart!!!!!!
Something`s gotten into my life 
Cutting its way through my dreams like a knife
Turning me up, turning me down
Making me smile and making me frown

I am still not sure but to me more times i listen to that more sure i am that it is Jane, besides, Jane is the woman name for John.