from the article excerpted below, I would say we have become the sex organs of the 3D printer, which exists only to replicate.. and to replicate itself rather than anything useful!
But what are these machines actually good for? PR representatives for HP and Stratasys make it clear that their new machines are for mechanical engineers and designers to make mock-ups and prototypes of new ideas (and for educators teaching the next generation, who will likely work in a world where 3-D fabrication is commonplace), but not for consumers: Despite HP’s reputation for building high-end consumer printers, this is not one of them.
And although the fully assembled machines have established a strong reputation for reliability, do-it-yourselfers must beware the 3-D equivalent of the paper jam, which often involves scattered blobs of solidified plastic, smoking circuit boards, or half-melted motor mounting brackets. Internet forums and builder blogs are full of stories about hours spent rebuilding extruders, days tweaking the alignment of build platforms, and nights rewriting the software that “slices” designs into layers that can be built up on top of one another without drooping or warping or overtaxing a printer’s tiny CPU. There is even a cottage industry of higher-strength spare parts for the kit components that are most likely to fail. If atoms are indeed the new bits, as the futurati have declared, then consider what the world will be like when mechanical objects are as buggy as the typical piece of software.
Indeed, at the hacker level, the most popular print runs seem to be 3-D printer parts. If you want something built for use, you might have better luck shipping your design to one of the rapid-fabrication services that have sprung up all over the world.