[Forbes reports on Shapeways], a 3D printing facility in Brooklyn, New York that can print by fusing nylon dust particles. Some of their jobs are so precise that they produce moving parts, machines, in the printing process. They can also print in metals. Clearly, this is the future for a lot of manufacturing. Why cast, mill, or forge when you can print?
The counter-argument to such a claim is that, given what it takes to set up a print job — in terms of 3D modeling in advance, there is a whole host of work, one-offs for which this might not make sense. I am also thinking of the kind of custom work that folks like the Olinger Repair Shop do.
[Forbes reports on Shapeways]: http://www.forbes.com/sites/andygreenberg/2012/12/10/inside-the-worlds-biggest-consumer-focused-3d-printing-factory/