The basic patents on fused deposition model link aka extrusion printing expired a couple of years ago. This led to an explosion in desktop FDM printers such as the Makerbot Replicator from individuals and companies we had never heard of. End result FDM for the masses and millions of dollars for the Makerbot founders and investors via there acquisition by Stratasys.
Next came UV laser cured resin printing. The Form printer from Formlabs is an early commercial success in this area with several more announced and/or being crowd funded on venues like Kickstarter and Indiegogo.
Seen on the horizon in the patent expiration Wild West are SLS And SLA printers which use powders and lasers to print parts in monochrome, full color, and metals.
I can't wait to see what come out in the next year.