Idea Proposed and Used to Death during the New Series: We are now three for three this year for stories about fathers who are having trouble relating to their sons and wind up bonding with them. Did I mention that my least favourite film in the world is Nine Months?
Central Premise Recycled From: "Rose," which has to be completely deliberate. Also the idea that babies have a secret inner world as galaxy-conquerors who view the rest of us as peasants is a running gag in Family Guy, among others.
Reference to Moffat's Back Catalogue: Small child, the abovementioned parenting issues, Doctor as saviour of children, River bloody Song (and just when I was starting to like her...), creepy nursery rhymes, running gag where people assume two straight friends are a gay couple (c.f. the recent Sherlock Holmes).
Craig Screws Up the day with Wuv: And then saves it again.
Russell T. Davies Called...: He wants to know who's condensed his entire era into fifty minutes. Neil Gaiman would also like bits of Anansi Boys (cool guy who gets away with things paired with normal guy who tries to do the same things but can't get away with them) back.
And from Lawrence Miles: Babies feature as characters in both of the FP audio series.
Murray Goldwatch: Has gone back into soundtrack-for-kids'-movie mode.
Nostalgia UK: Arguably, the saucy slapstick comedy-of-manners in the abovementioned running gag about gay marriage. And Lynda Baron (she of Captain Wrack's Cleavage).
Inside Jokes: The phrase "Spare Parts" is repeated over and over. When a little girl asks Amy for her autograph, then looks excitedly towards the Doctor, one can't help but suspect she's telling her mother "I just met Karen Gillan and Matt Smith!"
Teeth! On the Mat!
Hats! Stetsons are only cool if they've been given to you by John Wayne.
Fish! Alas no. I miss them.
Small Child! Lots and lots of them, not even counting the co-star.
Item Most Likely to Wind Up as a Toy: We're going to get another lot of Cybermen, these ones rusty. Aren't we.
Title explained here.