And please, feel free to shout this down as the stupidest idea ever. I haven't yet seen the new movie. I will, on opening night. I have a hunch that the plot from the next movie will in fact tie into this movie, but...
The Enterprise is well into it's five year mission, when they detect waves of temporal distortion emanating from a planet: yes we're going to find the Guardian of Forever, total fanwank, I know. This time however, Kirk and Spock are met with a dilemma. The two most formative events within this timeline never occured within the prime timeline, the death of George Kirk, and the destruction of Vulcan. They realize that they may be able to change these circumstances saving not only Kirk's father, but Spock's mother, and the entire planet of Vulcan in the process.
The ethical conundrum ensues with the conflict of not only whether they should act to change their own history, but in their knowledge of the "black ops" arm of starfleet, whether they should reveal the location of this device to the Federation.
It's just a germ, and a fanwank one at that, but I think there could be a plot there. And it wouldn't involve a "villain" bent on destroying our heroes, but on decisions they make in order for their timeline to continue.
Go ahead-tell me it's fanwank crap that would make a terrible movie (I already kind of think it) or is there something there that might work?