The Doctor: Call 'em what you like — the Daleks are death. Churchill: Yes, Doctor! Death to our enemies! Death to the forces of darkness, and death to the Third Reich! The Doctor: Yes, Winston, and death to everyone else too.
Bittersweet Ending: The Doctor fails to prevent the five new Daleks from escaping to rebuild the Dalek race, but Amy manages to save Earth and allow Bracewell the chance to have a normal life free from Dalek control.
The concept of Daleks pretending to be servants goes all the way to the Second Doctor's seasons in "The Power of the Daleks". Specifically the line "I am your sol-dier." is a direct Shout-Out to the Dalek's sycophantic "I am your ser-vant." in that episode.
The Progenitor Device itself was first introduced in "The Power of The Daleks", as another one had crashed on Vulcan. This episode clarifies its intended purpose.
A Dalek using its toilet plunger to carry a tray full of nibbles for people? Surely this has never happened befo— oh wait, they did it in their very first episode.
Changed My Jumper: Amy wears a miniskirt in 1941 without comment. Though between the ongoing bombing of London and the Daleks threatening the planet, some woman's bare legs were probably the least of people's concerns.
Cliffhanger Copout: Sort of; the end of "The Beast Below" has Churchill urgently calling the Doctor while a Dalek looms ominously in front of him, with the suggestion that he's in fairly immediate danger. The resolution? Apparently that call was weeks ago, and Churchill's got used to having the "Ironsides" around.
Comically Missing the Point: A more heartwarming example than usual; when the Doctor and Amy go to say goodbye to Bracewell, they find him in his lab, preparing to Face Death with Dignity as he assumes that the Doctor and Amy are planning to deactivate him as a potential threat to the timeline. The Doctor, rather surprised (since they were actually just popping along to say goodbye before leaving), agrees but says that he has to go and do some stuff first, and it'll probably take him a while, hint hint. It takes Bracewell rather longer than it probably should to realise that the Doctor isn't going to be coming back.
Fantastic Racism: The Daleks' commitment to their own racial purity was demonstrated here. The older, less "pure" Daleks willingly allow themselves to be disintegrated by the newly created Daleks made from the pure DNA in the Progenitor device.
Heroic Sacrifice: From a certain point of view, the Daleks. What else would you call taking a course of action to save your entire race knowing full well it will end in your demise?
I Need to Go Iron My Dog: That super important thing that the Doctor has to go do, but he'll definitely come back and deactivate Bracewell after he does the thing. Gonna take a least half an hour, then Bracewell will be so very deactivated.
Just Plane Wrong: The Spitfires used in the episode were Mk IXs, which were introduced in 1942. They should have been Mk Is or IIs, which flew in the Battle of Britain. Then again, they were IN SPACE!
Kick the Dog: Forcing all the lights in London to turn on at the height of the Blitz? That's an impressively dickish move, even for the Daleks.
Kill 'em All: Subverted; surprisingly for a Dalek episode, this has a relatively low explicit body-count (two soldiers, about 12 planes shot down and 3 Daleks). Compared to the decimation of Torchwood One, this is very low.
My Greatest Failure: The Doctor considers his inability to stop the Daleks to be his, lampshading the ridiculous number of ways in which they always come back, but in a cruel way. Doesn't help that he just let five escape with a Dalek-creating machine.
Daleks infiltrating Earth by painting themselves olive green and insisting they don't even know what Daleks are. Their entire plan even hinges on The Doctor inevitably showing up to try and foil their plans.
Not to mention the climactic scene of Independence Day, in which a lone human aircraft takes on a large alien saucer-like spaceship.
"If Hitler invaded Hell, I would make at least a favourable reference to the devil."
Amy, near the end of the episode, says to the Doctor: "So you have enemies?" This is part of a famous Churchill quote: "So, you have enemies? Good. That means you stood up for something once in your life."
Smoking Is Cool: Played with. Despite there being plenty of smokers in Britain at this time period, the only person we see smoking is Winston Churchill, the penultimate Big Good of the British in WWII. However, this is more to stay true to the character, as Winston was well known for enjoying quite a few cigars (and quite a few glasses of brandy, something not even shown here most likely for the sake of the kids, and it's considered one of the icons of his (especially wartime) visage. A bit of Fridge Brilliance takes place when the Doctor declines a cigar from Churchill after saving the earth. At first it seems like an aversion of the Smoking Is Cool Trope, and while that is obviously the case, it also doubles as something else entirely. Cigars being shared is usually a sign of celebration, and while the Doctor DID save the earth, he personally doesn't have much to celebrate, considering the Daleks beat him with a Batman Gambit, only doubling the reasons why he'd not accept a cigar in these circumstances.
Somebody Set Up Us the Bomb: Subverted. Bracewell turns out to be a bomb, but the Doctor and Amy encourage his burgeoning humanity to deactivate the bomb... somehow.
Space Is Noisy: Laser fire from the Dalek ship and the British Spitfires can be heard.
Stupid Jetpack Hitler: Inverted. Winston Churchill gets to use advanced alien weaponry against the Nazis.
Tomato in the Mirror: The scientist, Bracewell, who didn't make the Daleks... the Daleks made him, an android. Another revelation exposes Bracewell to also be a bomb, which the Daleks threaten to detonate (and try anyway) to make the Doctor return to Earth. Turns out they made him toowell; his self-awareness and genuine emotions turn out to be the key to stopping them from destroying the planet.
With a twist — Radio Timesspoils new Daleks on a cover again. Unlike "Daleks in Manhattan" though, the new Daleks' cover appearance was explained away as the cover being themed around the 2010 British Electionsnote With the red, blue and yellow Daleks representing the three main parties; the orange and white ones understandably do not appear on it. rather than them being an important development in the episode.
Played straighter in a BBC news report which featured behind the scenes footage of the filming of the scene where the new Daleks are revealed the day before the episode actually aired.
V Sign: It's a Winston Churchill episode... Although it's actually done by the Doctor, and he seems to use it to wave at people.
Unwitting Pawn: The Doctor falls for the Dalek plan twice throughout the entire episode.
The War Room: The Cabinet War Rooms really existed during the Second World War, although they weren't used for fighter control (an old emergency bunker in Swansea was used for filming). They're open to the public and are pretty awesome anyway.
Weirdness Censor: Subverted; the Doctor quickly asks Amy to fill Churchill in about the Daleks, only to find she has no memory of them or the whole "planets in the sky" incident. He's very disturbed by this, and at the end of the episode declares that they need to find out what's wrong with her memory.
You Have Outlived Your Usefulness: Played With. Once the new daleks are born, they first action is to exterminate the three old Daleks due to not being pure enough. The three daleks not only are aware this was gonna happen, but are perfectly OK with it.