Tim Kang (Cho) tweeted something the other day that looks to me like a final goodbye:
Tim Kang ‏@Tim__Kang  18hAnd...that's it for me for Season 6 of The Mentalist.
Thank you all for your love and support! It has been an amazing 6 years!!

And that Karl guy is suspiciously thanking all the fans for their love and support..They usually never do this after a season..

Even though I hate the new direction of the show, I will be very sad when we hear the news that it is cancelled..Seeing these tweets makes it more real.:(