I'm sure of one thing. It would be really stupid to show Red John already in a promo.
I think that the scenes in the promo are just some seconds of chasing  someone else who works for him.
I mean come on The Mentalist is made in a film world where they make film. The most simple thing to know is that a film is build on  24 frames per second. I mean Bruno Heller should have known that people will pause every frame to see who 'Red John' is. Even the tabloids..
And until now he never showed the most important suspect in a promo, so why will he show RED JOHN now of all the suspects? And the stuntman of Thomas McAllister admits he is in the show just like that? There is more behind this. 
It is like Bruno Heller wants that the viewers will all focus on the man who jumps through the window.

PS:
Robin Tunney(Teresa Lisbon) they had a 7 year contract, so we can expect a season 7.

Cheers.