15 Second Potter trailer with Dark Knight. Earlier in the week three trailers were confirmed for the Dark Knight release: Watchmen (yay!), McG’s ‘Terminator Salvation: The Future Begins’ and the Ridley Scott directed ‘Body of Lies’. Now it seems a trailer for ‘Harry Potter and the Half Blood Prince’ has been confirmed for the film – at least in IMAXs. According to an Imax spokesperson, “there will be a SHORT, 15 second trailer for Harry Potter and the Half Blood Prince prior to The Dark Knight.” It looks unlikely the Potter trailer will be shown in traditional theatres so all you Potty Potter fans, off you go to England for that 15 second (ha!) IMAX experience. The Dark Knight is in Irish cinemas July 25th.