The excitement comes from the combination of a few factors: 1. It's improving very quickly, both in terms of the materials you can print and affordability of t

The excitement comes from the combination of a few factors: 1. It's improving very quickly, both in terms of the materials you can print and affordability of the hardware. It's possible to 3d print powdered metal composites, for example, not just cheap plastic. 2. It makes possible entirely new manufacturing business models. Traditional factories will probably always be cheaper for mass-market goods, but there are likely to be lots of opportunities for niche-market goods that simply aren't economic under a big-scale factory model. Maybe even more importantly, the existence of 3d printing makes it easier to bootstrap a manufactured product -- you can start out 3d printed, and only go to big-factory-mode much later when demand dictates. 3. By bridging the worlds of software and physical goods, it holds the promise of unleashing open-source methods for the design of things, not just software and information.