The trailer starts out on a haunting, dark note — Matt Smith is walking in the TARDIS, while in voiceover he says, "I've had many faces. Many lives. I don't admit to all of them. There's one life I've tried very hard to forget." And we glimpse the Doctor talking to Clara about his greatest secret.
And then — what looks like the Time War, between the Daleks and the Time Lords! Seriously. Daleks blowing up, flames everywhere, everything going to Hell. And in the middle of all the carnage, John Hurt as the non-Doctor, looking resolute. "Great men are forged in fire," he says. And then something about being the man who lit the flames.
And then, we get Tennant and Smith. Tennant, in his TARDIS, yells "Allons-y," while Matt Smith, in his, yells "Geronimo!"
Rose pops up and warns that "the moment is coming." And John Hurt's non-Doctor says that he is ready for what's going to happen.
And then: the Tenth and Eleventh Doctors comparing their sonic screwdrivers, as Tennant looks possibly a bit jealous of Smith's screwdriver. And then a shot of both of them wearing clever glasses, while Smith wears his fez and they look delighted with their cool gear. And then a glimpse of Rose, looking excited.
Oh, and the TARDIS being airlifted down to Trafalgar Square with the Doctor hanging down from it.
Smith is in the TARDIS, when he says, "I remember this. I pretty much remember." And we see twinkly lights traveling across the Earth.
David Tennant and John Hurt are inside Matt Smith's TARDIS. "Oh, you've redecorated. I don't like it," Tennant says, channeling Patrick Troughton in "The Three Doctors."
A title appears: "This fall, the Doctor will face his darkest day: Himself."
And we see Zygons, plural. Busting out of a glass case. And then some more shots of Daleks blowing up and being torn apart and generally being Da-wrecked.
Inside the TARDIS, Tennant tells Smith, "For once, I would like to know where I'm going." Smith responds: "No, you really wouldn't."
And then, someone says, "I'm looking for the Doctor." And the camera pans around to show Hurt, Tennant and Smith, with the two Doctors trying not to look at their unacknowledged predecessor. Tennant shrugs and says, "Well, you've certainly come to the right place."
So it does look like Moffat is just going to toally ignore the fact that both the 9th & 10th Doctors took responsibility for their actions in the Time War and shift all the "blame" onto 8.5.