I would guess that in a couple of days we know who the villain of Star Trek Into Darkness is. I would assume that his name will pop up in the first nine minutes of the movie that plays at IMAX theaters in front of The Hobbit: An Unexpected Journey, or in the trailer that will be debuting at the same time. Even if Benedict Cumberbatch's villain doesn't get an actual name, we should get enough information to figure out who he is. I am fairly certain he won't be Gary Mitchell, who was the antagonist in Where No Man Has Gone Before, Star Trek's second pilot episode.
In an interview with TrekMovie, writer Roberto Orci stated that Cumberbatch is playing a canon character - ie, a character who appeared in the original series. In that same interview, which happened this past July - well after filming - this exchange about whether comics and games overseen by the current filmmaking crew should be considered canon:
TrekMovie.com: The difference with previous Trek is that you guys are overseeing all of [the expanded universe content]. These rules aren’t written in stone from my perspective and I think a lot of fans would like to hear you say, "yes these are all the adventures of Kirk, Spock and the gang and it is all canon and all ties together into a single universe." Again, with the caveat that you reserve the right to contradict any of it in a future movie and that would trump. That’s my pitch to you.
Roberto Orci: OK, based on that then with you Anthony Pascale as a witness, I hereby declare anything that we oversee to be canon.
TrekMovie.com: OK! Do we need to get that in writing? Do we need to get the ghost of Gene Roddenberry to notarize this?
Roberto Orci: Let’s call his son Rod, I’ve got him on speed dial.
Why is this important? Because in the IDW Star Trek comic, overseen by Roberto Orci, Gary Mitchell has appeared and been dispatched.
Years ago I had sources tell me that Gary Mitchell was in fact the villain in Star Trek 2, but that was before serious work started on the film. My understanding is that Mitchell is who Orci and Alex Kurtzman wanted, but JJ Abrams or Paramount or a combination of the two decided otherwise. As a result, Mitchell was given to the IDW comics, which published his story in late 2011. This would have been while Star Trek Into Darkness was in pre-production; the actual comics would have been written earlier, but presumably at a time when Orci and Kurtzman knew that Mitchell wouldn't be their villain.
Is it possible that Orci is lying? Yes, it's very possible. Lying is what people in Hollywood do. But if he's lying about this he's essentially undermining all of the expanded universe ancillary Star Trek stuff immediately, which is bad business sense. And these guys are business first, make no mistake about that.
If he's lying in that interview he's also being a huge dick, and he's doing it right to the core fanbase. There could have been ways to get around answering that question directly, or to answer it in such a way that it leaves out Gary Mitchell (Ie, "I hereby declare anything that we oversee from here on out to be canon"). A lie here would be hugely disappointing, on a basic human level.
Of course canon doesn't really matter, but this is Star Trek. Fandom as we know it today exists largely because of Trekkie obsessions with canon. This is real geek stuff, parsing timelines and attempting to make contradictory information line up. You haven't experienced real geekiness until you've argued with a Trekkie over whether Star Trek: The Animated Series is canon. And just try getting into a conversation about how the timeline shift in the Star Trek movies impacts Enterprise's Temporal Cold War.
I'm choosing to believe that Orci, whatever I think of his screenwriting and his politics*, is an honest guy. While I disagree with a lot of the stuff he rants about on his Twitter account, he's incredibly honest about it. To me this means there's no way that Cumberbatch is playing Gary Mitchell.
* they're insane