A company in my work history has been using rapid prototype machines for _30_ years to make patterns for investment casting. Aint nothing new under the sun.
No, it's most certainly new. That is unless your company paid well under 5 grand for those rapid prototyping machines. Oh, you have to build the machine without using a real lathe, mill, or any other tooling we are all used to having. If you've ever seen a rep-rap style machine first hand you would be impressed at what they can do for all they are. Basically, nothing but a bunch of all thread held together by parts printed on another cheap 3D printer.
All the software and programs you need to run the thing are free too, coded by people that aren't necessarily professional software developers and shared with everyone else with no intention of profit or fame. That in itself is amazing.
If dude wants to print a lathe, so what? Maybe it's just a model, or maybe it's just a demonstration of the capabilities of the 3D printer. A few years back printing something like that would (most likely) have been unheard of.
Nobody anywhere is trying to make money with this style of 3D printer, at least anyone that has any business sense. So there is no real reason to "prove" the capabilities of the machine to anyone other than yourself.
As for the "CNC mill" made from pipe fittings, I think it's pretty impressive. I wouldn't have thought of that. These guys making this stuff don't have access to real machine tools, they make do with what they have which is usually just random hand tools and cheap materials from the hardware store. Imagine if you gave them a rack of steel, a real CNC machine and some good design software...