I love The Mentalist.. I've got a feeling that Red John is someone we know as it was revealed that he'd shaken hands with him at some point... but bear in mind once he's found Red John that will be the end of the story.. and *sob* no more twinkly Patrick Jane...
It is driving me a bit nuts now, how many series in are we and still have no idea. That FBI agent must have some connection but I doubt he's Red John, that'd be too easy.
I hope it's not Cho or Rigsby.
I reckon it could carry on okay, life wouldn't be the same without Patrick Jane.