No, 3D printers are suited for fast prototyping, and also to build low production scale mechanical parts for which cost is less relevant than delivering time. In other hand, I would say that 3D printers are affecting and will somehow positivelly impact on production industry, once for many cases it is possible to quicly manufacture replacement spare parts even for temporary use while the final component do not arrive from supplier. I met a person who are developing a process to manufacture carbon fiber and build small parts for specific customers with that substance.