If you didn't see SPOILERS in the topic title... let me say it again...
SPOILERS.
Okay, details of the finale movie have been posted up with the pre-order for the DVD & bluray... and it tells us a number of things that happens in episode 13 of this season.
A resurrected UNICRON has taken over the now-lifeless body of MEGATRON to seek vengeance on the AUTOBOTS and ultimately, the destruction of Cybertron. This formidable enemy forces an unlikely alliance between the AUTOBOTS, DECEPTICONS, PREDAKING and two new Predacons, who come together in an epic battle to help protect their newly restored planet!
Well... it certainly explains one of the Cmdr class toys coming out at the end of the year (Unicron Megatron). It's certainly a plot spoiler now, but the name originally just looked like a random prefix being added to a redeco toy.
DVD is out in America October 8th, and on bluray October 1st. It doesn't sound like it will be aired on TV any time soon (in America).
(looks like I guessed the title correctly, a few months back, assuming that the Target Exclusive line was the name of the movie it was being released for)