Doctor Who: The Impossible Astronaut

Doctor Who has started again! This gives me a way to get back into the habit of writing regularly, after a couple of off weeks. Before I start, though, here's a warning from River Song.

Spoilers!

Saturday's episode lulled into a false sense of security with The Doctor messing about in history, and then brought us to the picnic, where Amy caught her first glimpse of The Silence, and a the Astronaut appeared out of a lake and assasinated The Doctor. As Rory decided to give The Doctor a Viking Funeral in a burning boat, I'm wondering if this was "The Picnic at Asgard" that River referred to in Silence In The Library. After meeting a younger version of the Doctor, we headed to the White House in 1969, where we met Richard Nixon. Whereas historical characters have been major parts in previous stories, here Richard Nixon was more of a supporting character. The episode was really pushing Steven Moffat's trademark mixture of scares and weirdness to the limit. There are a load of unanswered questions, including

• Who are the Silence? It's implied that they were the behind the scenes villains of last season, and their ship is the same as the one seen in The Lodger, but we really don't know anything more of them than that.
• What do they want?
• Can Amy save the Doctor, and if so, how?

But the one that's intriguing me most is Why were Amy and Rory at home at the beginning of the episode? Last time we saw them, they were happily travelling with The Doctor and showed no sign of wanting to go home. River said that it would be dangerous for The Doctor to interfere with his own timeline, but maybe everybody's timelines have already been interfered with, and need to be put right.

Also, could this be when The Doctor tells River his True Name? When she revealed that she knew it in Silence In The Library, The Doctor said there was only one reason why he'd tell it to anybody. Could the reason be because he was going to die?