Having read Alastair Reynold's stuff, I thought the idea of replicators was awesome. My current thinking is that 3d printers, if they master multiple materials, will kill off mundane manufacturing. I can't see it being a bad thing, albeit an industrial revolution style shift.
I find it hard to see them as a threat to industrial manufacturing. Is there anything that a 3D printer can produce for cheaper and/or creating less pollution, if we account for the shipping of raw materials to a person's house and give any value to his or her time assembling things?
3D printers are a movement in that direction, that ends with mini factories or replicators.
Replicators will be the death kneel of the factories.