While in this particular instance the term "replicators" better fits the Stargate SG-1
definition (think chip-size TNG Borg) than the Trek
definition, elements of both are present.
The RepRap is a self-replicating rapid-prototyping machine. I've seen a large rapid prototyping device before at a university, and they are magnificent devices. Building a plastic object layer by layer, you end up with a near-perfect model (or, if it was a plastic object you wanted in the first place, a near-perfect object ready for use).
Calling it "self-replicating" is a bit of a stretch at the moment. In addition to a wealth of additional parts (including steel rods and assorted electronics), it must be hand-assembled and requires a computer to operate. However, future RepRaps are intended to have the ability to do circuitry. This sort of thing is manually possible even now . . . there are special conductive-ink pens that allow one to draw working low-voltage circuits. Microprocessors are certainly a long way off for any such tabletop technology, but the germ of the idea is there.
Even with what it can do now, it would be theoretically possible for RepRap to put certain companies out of business, if the units existed in sufficient numbers. For the most low-key example, you can imagine a simple "make solid" plug-in to convert 3-D graphics models (LightWave or POV-Ray or what-have-you) into solid shapes that the RepRap software could build. This would have the effect of savagely reducing the business of certain fringe model kit and toy makers. Even for more advanced model-builders who wanted to light their models, designing little conduits (or large open spaces) for running wire or fiber optics is hardly outside the realm of possibility.
The best part of
RepRap is the
open-source nature of it. You can make your own right now.
The active mind can certainly see all sorts of potential for a device like that. But, I want you to imagine the future. Picture a replicator similar to RepRap capable of working with many materials. I'm not even talking about nanotechnology dreams, here, but a real assembler capable of using small quantities of metals and plastics. Even with the most basic processors, what common items couldn't be made with such a thing?
This is the coming revolution. While industry will remain a step ahead for a long while owing to quantities of scale and special needs and whatnot, home manufacturing will slowly whittle away at it as time passes.
Of course, the more things can be made simply, the greater the danger, too. If you can make a simple analog telephone at home, you can make a sealed detonator circuit just as easily. The same is true even today, to be sure, but with so severely lessened cost and thought and effort requirements I have a feeling the problem would worsen significantly.
Will we make it past a home manufacturing revolution? Will nano-tech based home replication systems come and will society survive? It remains to be seen. But we're not too terribly far away now from finding out. The world of 2100 will either be extraordinary to see, or positively horrifying.