Spoilers will abound. You're duly warned.
It's the whole thing about robots. Are they robots? Are they regular people who have computer chips implanted in their heads? There are points that say it could go either way.
1. Faith Hill's character, Sarah Sunderson, seems to short out when at a dance and starts repeating herself and twitching (like a poorly wired robot). When she finally collapses, and just before Christopher Walken does something to her head, you can see sparks coming out of her ears. Joanna (Nicole Kidman) mentions that she was "sparking"
2. Later, Joanna, Bobbie, and Roger are trying to see if Sarah Sunderson is okay and they find a remote labeled "Sarah". When they press the remote we see (but they don't) Sarah's breasts growing, and then Sarah pauses and moves up and down the stairs in a robotic manner...as she responded to the remote.
3. When Bobbie is turned "Stepford", she places her hand on a stove while talking to Joanna. Her hand is directly on an open flame and there is no reaction. Even if she has an implant in her head, can a human do that?
4. Joanna researches the citizens of Stepford and finds that all the women were once high powered executives and judges and stuff. She also finds out that there was a dog that went missing...a dog that looks sort of like her new robot dog. Hmm, robot dog and robot people?
5. Near the end when Walter removes the "Stepford" program, there seems to be a flash of light from the bodies of the women.
6. Walter says that Joanna is not a robot.
7. When Joanna confronts the group at the Men's Club she sees a mostly finished robot on a table, it is implied that it is Joanna's robot.
8. There is a woman that is an ATM (inserts the card in her mouth, spits out money a few seconds later)
9. Mike is a robot (visually proven)
1. Mike (Walken) shows a advertisement for Stepford Wives, where men can bring their women in and computer chips will be implanted into their heads to make them more "perfect".
2. When Walter is deprogramming the women, there is no real conclusion that it isn't just the chips having the programs erases. Combine this with point 1, and the suggestion is no robots.
3. When the programs are erased, all of the Stepford Wives regain their original personality and have control over themselves again (best example: Roger).
4. Claire (Glenn Close) is not a robot.
5. There is no robot discussion at the end of the film where Bobbie, Roger, and Joanna are on tv talking about the whole Stepford experience. Remember, Bobbie and Roger were Stepford-ized.
The evidence that i can remember lines up more on the robot side, which makes sense because i think they were robots in the original source material, but...the film doesn't do a good job at making a decision on what they are. I don't accept that Frank Oz is leaving it up to the viewer because he doesn't give sufficient evidence during the film (because of the contradictory evidence) and also because the plausibility of the ending depends on whether or not they are robots. The ending works if they are not robots, but if they are not robots...the film doesn't work very well because the film leans more on the side of the wives being robots.
Sure, the ultimate suggestion of the film has to do with the feminist movement of the 70's (which is when the original was released...which puts it into a deeper context) and that what all men really want is a wife to take care of the home, sexually satisfy him at his whim, and to be physically perfect...and to not have a brain in her head because men are really threatened by a strong woman. And to accomplish this, men would rather have their wives be docile and submissive robots than be real, flesh and blood women.
But the movie doesn't really go there, does it?