So I was reading the morning spoilers about.....
River Song's involment in the possible season finaly and I thought about the whole "Silence will fall"thing.
A thought went into my head that maybe the library in "Silence in the Library" would be destroyed if the Doctor answered the question, or that the answer given would somehow release the minds of the people that are in the cyberspace.
Now here me out on this, let's say that they want to keep the actress who plays River (Alex Kingston) around more, but they have to admit she is aging. So what they would do is that the place were he answers the question would trigger some type of release or create some type of object that allows the cyber people to return whole once again.
So in theory, the silence will fall when the question is answered cause the answer is the key to release all (or create real bodies) of the ones who have been digitized.