The official site has updated with introductions to the new series and The Impossible Astronaut - see them in the players above and below. They are taken from Doctor Who Confidential, the "making of" show. More details:
Episode one is called Coming to America and covers the stunning stateside filming, the return of River Song and more. Featuring interviews with Matt Smith, Karen Gillan and Alex Kingston, Doctor Who Confidential is on Saturday, 7pm on BBC Three.