Pretty cool stuff.
I work in the manufacturing industry and use Solidworks which makes 3D computer models. I've actually seen a few of these things run before.
Now that they are cheaper and more efficient they will have an effect but
I don't know if I agree with it being the greatest change in human history. I think it will have a similar effect on the business/manufacturing/sales landscape that the internet did. It will allow smaller companies to compete and adapt better. i.e a company can consist of 1 guy with an idea that made his own website and has a 3D printer in his garage and makes parts as he gets orders for them. Instead of having to pay someone else to make them and be forced to buy 10,000 units per cycle.
I think these things will have their place in the big picture. I don't see them ever being efficient enough to replace casting, stamping, and molding processes which can produce multiple parts in seconds or minutes.
I do think it is cool that you can create parts that have never been possible to make before.
Also i didn't know they were using other materials now. The ones I have seen run all used various plastics.
