Re: @mr.K
I just rewatched the end of series 5 - the Pandorica story - and right at the end, as Amy and Rory, just-married, enter the TARDIS, the phone rings...
And during the conversation the Doctor says "no I get that it's important: an Egyptian godess loose on the Orient Express, in space".
I have to say I sometimes wonder how far in advance "the Moff" plans. Did he have the entire River Song saga in his mind when he wrote Silence in the Library, for example?
Anyway, just thought i'd mention it.