Here’s my simplified idea of what factories do: they make a whole lot of copies of one thing really cheap.
The “really cheap” part only comes with scale. Factories don’t make “a few” anything. They’re dependent on a mass market economy. Things need to be cheap enough for the mass market to buy them, but they also need to change constantly. As humans, we have an appetite for novelty. As the speed of innovation increases, factories spend more time retooling as a result.
Where does this trend point? We’ve already seen low cost small scale fabrication machines popping up, like MakerBot and CandyFab. These are specialized versions of 3D Printers. Digital sculptors can design their sculpture in software, press print, and voila, the machine prints a copy of their object.
Now imagine a machine that’s part 3D Printer, 6-axis robot, laser cutter/etcher, and circuit board fabricator all-in-one. Imagine our little machine has conveyors feeding it stock parts from a warehouse out back, just waiting for someone to download a new design.
That kind of “fabrication” machine would be a designer’s dream. In fact, I don’t think our current pool of designers could keep up with demand. Everyone could take part in design and expression.
I don’t see any reason why this fictional machine is actually beyond our technological capabilities. It’s certainly very expensive to develop (I’m going to take a stab and say it’s roughly a complex as building an auto plant), but once you’ve made one, we have the capability to make many more.
For more ideas, take a look at what MIT’s Fab Lab is working on.