I have a feeling that, at scale, 3D printing will become just like CNC machining. Anyone can buy a cheap CNC machine on eBay, yet, from that to using them for non-trivial manufacturing and prototyping work it is a whole other matter.
Today you can buy 3D printers for as little as $100. I bet most of those sit around collecting dust after someone printed a rook, Darth Vader's head, the Eiffel Tower and a few models they downloaded here and there. In other words, they end-up exactly where drones do after the initial love affair.
It should come as no surprise that the majority of actual consistent usage is in professional and manufacturing applications. Be it research in prosthetic limbs, prototyping or limited run specialized parts.
I believe these sectors will continue to grow and require constant improvements in technology. My guess is this is where opportunities lie, not with the now very tired idea of kids making their own toys at home you see in nearly every single Kickstarter campaign.