It Was His Sled: The Robotic Reveal of the original was the film's shocking surprise ending. Thirty years later, when the phrase "Stepford Wife" had entered the lexicon, the remake assumed audience familiarity with the concept and played it for laughs.
Real Life Writes the Plot: Screenwriter William Goldman's original vision of the 1975 film had the Wives all dressed like "Playboy Bunniessans ears and tail". Then director Bryan Forbes cast his actress wife Nanette Newman as one of the Wives, and whatever talents as a thespian she possessed, her physique wasn't remotely up to it. The story was changed to have all the Wives ended up in long flowing dresses that made them look like '50shousewives. This may have been for the better, as one of the book's key themes was how the women were unwillingly pressed into domestic servitude and forced to give up their ambitions, and the housewife outfits highlight that much better than the skimpier outfits originally planned would have.
The remake goes both ways with this, giving the robot wives short, form-fitting sun dresses that highlight their figures.
The scene where the husbands use one of the wives as an ATM.
There's also the unstoppable twirling scene and the remote control breast size scene. These were actually meant to be rather blatant Foreshadowing, but were rendered bizarre because of the last minute change to the ending.
While a lot of critics slated the film for taking a comedic approach to the storyline rather than the more serious tone of the previous adaptation, the original novel actually was more comedic in tone than the 1975 film. In fact, that film was actually supposed to be as comedic as this one, but director Bryan Forbes rewrote it and eliminated most of the humor.
The twist of the wives merely being lobotomized, rather than murdered and replaced with lookalike robots, might have came from the sequel films, which also performed this retcon so that the victims could be saved in the end.
Shocking Swerve: The 2004 remake ends with a twist: the wives simply have chips in their brains that are easily deactivated, rather than being robot doubles, so we can have a happy ending. This creates a large plot hole, as it contradicts a few scenes like one of the wives acting like an ATM and spewing dollar bills from her mouth, or the Camp Gay guy apparently looking at his robot double in horror. One deleted scene with Bette Midler's character going nuts with various housecleaning accessories in her body makes it very clear that they were originally intended to be robots.
What an Idiot: As The Blockbuster Buster pointed out, the husbands should've been put in jail for what they did to their wives...instead their punishment is house arrest and having to perform regular chores performed by the Stepford Wives and are still married to their wives...whom they've tried to brainwash and enslave their wives.
Blockbuster Buster: It's funny because they should be in jail, for consenting to the illegal performance of brain surgery on their wives as well as enslaving them but instead their punishment is to perform everyday common chores for their families.
Though it may have been part of a plea deal with the authorities. Those same husbands were privy to advanced technology in various fields including robotics, cybernetics and neurosurgery. That would benefit humanity greatly and would definitely be worth a reduced sentence or special conditions.
Whether they are still married is questionable. They may be husbands in name only as their wives have very solid (and favorable) grounds for divorce. Plus, we only see one scene of the husbands during their house arrest and they're clearly under surveillance. Finally, we don't see all the husbands; some of them may actually be in prison.