A statement from Bruno Heller to quieten that  whiny, pessimist inside all of us that thinks the ending will be a random  afterthought, with 100s of loose ends.

Bruno Heller -

"I know that everyone here is happy and pleased. Sometimes you're forced to hate the conclusions or the wrapping things up in silly, absurd ways or in fact — naming no shows — it turns out they didn't have any idea how they were going to end the show or what the secret was or why there were polar bears. We have the answers and it's very important to us, for those people who have been following us from the start, to reveal not in a series of cryptic moments that leave a lot of questions begged. We're going to tell the story and explain who Red John is and what happened and what is going to happen as clearly as possible because the audience deserves that."

http://www.whoisredjohn.com/See-a-theory-Red-John/10330