Gods, that is convenient, isn't it!?
And holy crap, that ties in nicely with a
wackjob theory I read that claims that the arc over the last few seasons ultimately aims to break the fourth wall, and have the Doctor acknowledge his own fictionality - a fact of which The Silence are already aware.
They watch the show, as we do, and that is why they knew about Rory's deaths, and why they know that to answer the oldest question in the universe - Doctor Who, the oldest question in the Doctor Who canon - would mean a narrative collapse, and an end to their credible existence.
The Answer to the question, that which makes Silence Fall, is "Matt Smith". Or Mr.Smith, to maintain some credibility in-universe, with the John Smith persona.
I
did say it was a wackjob theory.
I felt the finale was rushed, and the payoff at the end was rather predictable and anti-climactic.
I like some of the themes it's setting up, with the lower-key Doctor for next season, and the fact that they seem to be gearing up well in advance for the end of Smith's tenure as The Doctor, with "The Fall Of The Eleventh".
Of course, that could be wordplay, and refer to the fall of The Silence on the 11th of some date, or the 11th planet from some star, etc.
EDIT:
This article sums up (and elucidates) my feelings on the finale nicely.
