Two 60 second trailers come out with tons of scenes to talk about and we're talking about the term season
Back to more pressing matters, and wonder what's going on towards the end of the American trailer, Doctor says to an upset Amy "Whatever happens, however hard, however far we will find you". Who's 'we'
We is him, Rory and River I imagine. The TARDIS crew.
That line might also link in with one of Amy's lines from the Christmas trailer, where she asks The Doctor for a favour and he can't ask why. At least that's my housemate's theory.
there is a plaque on the TARDIS set talking about where it was built on Gallifrey, and which Gallifreyan workshops it was constructed in, and this has never been shown on screen — it's just there.