The proper trailer for the "Doctor Who" 50th anniversary special "The Day of the Doctor" popped up online early, got yanked, and now The BBC have released the official version.
The clip confirms the special will deal with the previously unseen Time War, and shows epic scenes of Dalek spaceship battles, the Time Lord citadel on Gallifrey, and John Hurt wandering a scorched planet. Rose's line 'The moment is coming' is another confirmation, referring to an artefact referenced in "The End of Time" which The Doctor used to end the Time War.
A second trailer is also scheduled to be released tomorrow and is said to contain a lot of new footage as well. See the trailer at Doctor Who Combom.