I'm not going to speculate on whether Cumberpatch is actually playing Khan, but since the new trailer ends with two hands between glass, one arm clad in yellow, the second in blue.....
Are we to believe that Abrams would deliberately tip us off AND make a conclusion THAT similar to WRATH OF KHAN? Part of me doubts that. It reels you in, but I'm going to go out on a limb and speculate that this moment will be in the middle of the movie and the arm will NOT belong to Spock. Mr. Blue is dying, I assume, but I believe the arm belongs to McCoy. And here's why.
The trailer has a noticeable Starfleet memorial moment with a the draping of a coffin. A VIP officer most likely, which leaves out Cupcake. I believe at least one and possibly up to three of Kirk's crew will bite it this installment. Before I saw the trailer at all I came to this speculation.....because to kill Spock in ANOTHER Part Two would be a repetitive unimagininity. So I think McCoy's days are numbered.
It makes dramatic sense to raise the stakes for Kirk, who almost certainly won't perish. Spock, again, has died two or three times, but McCoy hasn't died since ''Shore Leave.'' For Kirk to lose his ''first friend'' instead fits the bill. The Karl Urban clips looked fairly intense, and having him die would explain Chapel's scream.
As for Spock, he's already lost his mother and home planet. If he must lose somebody.....it'd possibly be Uhura. If she does go, I'm guessing they'll save that moment for the end.
We also have a scene segment with Kirk and Sulu running for their lives in a crimson cornfield, followed by a pensive Kirk close-up. Perhaps Sulu will die in this segment. These two have battled together and won in the first film. To both survive again would, like having Kirk and Spock's hands between the glass, would be too thematically redundant, at least to this writer.
So, in conclusion, I believe McCoy is definitely toast, Sulu may be victim two and Uhura MAY buy it at the very end. Three months from now, this post could be very prescient, or very embarrassing. We shall see.
PS: I'm thinking Bones will do the salute as a dying joke. Obviously it suggests Spock, but why would Abrams want to do that if the blue arm is dying?