I think that Patrick Jane is Red John.
Two things lead my theory:
- Only Patrick Jane can think like Patrick Jane. I mean the list of seven suspects, his secrets like his childhood memories. Moreover, they both know the psychiatrist (S04E02).
- Red John is afraid of altitude and, as we can see in the last episode (S04E03), Patrick Jane was scared on the church roof.

It is obvious, Patrick Jane is Red John... =(