Since Steven Moffat made it clear that if anyone leaked the trailer of the 50th Anniversary online, there would be no more extras at Comic Cons, no one has leaked the 50th Anniversary trailer. What did fans do? They leaked the other trailer. Here is the trailer for the docudrama An Adventure in Space and Time.
Please remember that as it is a leak on a camera, the audio/video quality is far from great. We will, of course, update you will better quality versions (hopefully official!) as soon as they are available.