Re: The Official Speculation Thread about John Hurt's "Secret" Doctor.
River being revealed as Amy's daughter was spoilered during the filming of The Wedding Of River Song, which was even before the season had started to air, In fact the scene went viral after being recorded on somebody's cell phone. Before that there was speculation but nothing more as with Clara.
The greatest science fiction series of all time is
Doctor Who! And I'll take you all on, one-by-one
or all in a bunch to back it up!"
--- Harlan Ellison, from his introduction
to the PINNACLE series of Doctor Who books