Yeah, as Dusty reported earlier, there will be a 9-minute trailer for Star Trek into Darkness shown alongside the iMax viewings of The Hobbit.
What he didn't report (likely cause it wasn't known until just now) is that several media sites have seen the footage already, and gave us some info.
Note that all of this is second-hand. I have not seen any of the nine-minute preview.
This is the level of spoilers you can expect from me. I ain't holding back.
SPOILERS BELOW! (including the identity of the main villain)
1) The main villain is John Harrison. He is a Starfleet officer, and appears to look Human. Other than this, nothing is known about him. This is a name that is brand new to Trek canon. Some sources claim it to just be an alias that they refer to him as until the trailer is released to the general public. Others say that it is his real name. After his appearance in the trailer, fans speculated he would be either Khan Noonien Singh or Gary Mitchell. Looks like neither was correct.
2) You can't tell from this screenshot, but this is actually the planet Qo'noS, the Klingon homeworld. And yes, we have confirmation that at least two Klingons will appear with speaking roles. No word yet on whether or not they will have their iconic forehead ridges, but it seems likely, as we did hear that they act like the warrior race that they appeared as in The Next Generation and beyond. And they will use bat'leths.
3) Alice Eve's character, previously unknown, has been confirmed to be Carol Marcus, that scientist from the second movie that Kirk got knocked up. Yeah. Should be interesting to see that.
4) The opening scene takes place on Earth. Specifically, in London on Stardate 2259.55. Using J.J. Abrams's method of stardate calculation from the previous movie, this literally translates as "the 55th day of 2259." For you lazy math people, that's Februrary 24th, aka my birthday. The scene opens with a couple having a baby. The baby is sick. Somehow John Harrison is tied to the baby. We don't know if he is the baby, if he is related to the baby, or what. But somehow, there's a connection. Placing it in 2259 means that this is one year after the events of the previous movie. Oh, and the screenshot up there is totally irrelevant, but I needed something.
5) That volcano scene from earlier that I overanalyzed as hell, apparently it's on an M-Class planet (read as: life-sustaining) called Nibiru. This is a new name to Trek canon, but not to real-life science. A quick Google search reveals that "Nibiru" is supposedly the name of an event that would happen if (theoretically) the Earth ever crashed into another large celestial body. inb4 Mayan 2012 speculation. That aside, could Nibiru end up crashing into another celestial body in the movie? Possibly Earth? We'll have to see.
6) Finally, (and tragically) we get one last scene. This scene is only attached to the trailer in the Japanese version, oddly enough. And yes, this is exactly what it looks like: Spock's death. Well, maybe. It looks remarkably similar, and they do supposedly play the exact scene line-for-line. (Compare it to the image that I posted before the break.) Could Spock be dead at the end of this movie? Or is J.J. Abrams just wanting us to think that?
If you want EVEN MORE SPOILERS, check out the official report here. I just tried to cover the important stuff. So I left a lot of things out. That link will have everything though.