Once 3D printers become standard home appliances, what will be the needs filled by old-style factories? Well, for one thing, we'll need someone to produce all our 3D printers, so there's that. There will also be other things home printers can't do, like milled metal parts or electronics. And with home 3D printers commonplace, consumer demands could shift quickly. The world of tomorrow needs factories that can take any complicated design, including electronic components, metals, plastics, rubber, foam, glass, ceramics and countless other material needs, and produce the finished product on demand, whether you need a thousand of them or only one. Those factories need to be flexible enough to produce cars today, rubber duckies tomorrow and telephones the next day without skipping a beat. It will probably have a different name than "3D printing" by that point.
Mokalus of Borg
PS - Probably something like "automated industrial manufacturing".
PPS - Or something cooler-sounding.