Idea Proposed and Used to Death in the Virgin Books Era: ...the above theme continues, with a trip to actual Area 51.
Central Premise Recycled From: "The Invasion of Time." No really, think about it. Also the Men in Black (who can, of course, wipe people's minds... and who inhabit a universe where aliens have walked among us for centuries).
Reference to Moffat's Back Catalogue: Leaving aside the kids, the spacesuit, the catchphrase, wibbly-wobbly-timey-wimey etc., we have magical Doctor-induced TV images saving the day, Amy-loves-the-Doctor-really action, "silence will fall" and about a million references to last year's season (celebrity world leaders, phantom pregnancies, Rory's past as a Nestene....).
Amy Saves the day with Wuv: Well, she makes Rory feel better with Wuv, but considering that her getting pregnant with Schroedinger's Child is going to be the catalyst for the action all season, I'd say she's got a lot to make up for.
Joss Whedon Called...: ...he wants his Ben and Glory bit back (remember how, in Season 5, anytime anyone found out that Ben and Glory were the same person, they immediately forgot it? Course you don't. Think about it.)
And from Lawrence Miles: Someone falling off a building and landing in the TARDIS pool.
Murray Goldwatch: In the very first scene, he manages to give us yet another musical theme consisting of a single percussive phrase repeated over and over with no variations. This wouldn't matter if we didn't know he could do better.
Nostalgia UK: And the Mad Men meme continues as River and Rory cosplay as Joan and Pete.
Inside Jokes: Dwarf star alloy, plus the Doctor tells Nixon to tape record everything, plus yet another trip to Manhattan (complete with confrontation in a partly-finished block of flats, Empire State Building prominently visible in the background). River cements her position as the female Captain Jack by making the exact same joke Jack does in "The Empty Child" about the lack of utility of a sonic screwdriver outside of the putting up of shelves.
Teeth! Still the anti-teeth!
Fish! Missing! this episode.
Hats! No, though River has a new hairdo! every five minutes.
Small Child! Who might well be looking for its Mummy.
Item Most Likely to Wind Up as a Toy: See last post.