I have absolutely no link back to this to back it up. For all I know it's some tabloid bollocks or it may have come from some really well-respected DW site.
I'm just copy and pasting what I read:
The seven episode sixth season kicks off with a two-parter set in 1960's America which Moffat has also penned. Filming is underway in Utah on the story which traverses from Monument Valley to the Oval Office, and shots of Amy Pond running in the desert can be found here. It's been confirmed that River Song (Alex Kingston) will play a big part in this story, while other guest stars include Mark Sheppard ("Supernatural," "Galactica") and Stuart Milligan ("Jonathan Creek").
Beloved comic author Neil Gaiman penned the third episode in which the TARDIS breaks down on an alien junkyard world where the crew encounter Idris (Suranne Jones), a woman who is preparing for death and has apparently met The Doctor before.
The fourth episode, penned by Mark Gatiss and entitled "What Are Little Boys Made Of", that apparently might deal with scary dolls that come to life on a modern day council estate.
Episodes five and six will be a two-parter penned by Matthew Graham ("Life on Mars," "Ashes to Ashes") in which "the Doctor will face a dilemma the like of which he’s never seen before". The titles are rumoured to be "The Rebel Flesh" and "Gangers", while a snipped from the show's official mag makes mention of The Doctor recalling events from the Tom Baker era in the 70's.
The seventh episode is the first of a two-parter which will be resolved when the show resumes in the Fall. Moffat is penning this one and says this is where a major revelation about The Doctor is made, and is the one where we learn the truth about River Song.
Presumably it comes from an American site given the use of 'fall'...