That's true to some extent, although it's useful to keep two things in mind:
1) The improvements in the output of FDM printers is in good part due to switching to lower-strength materials (e.g., ABS -> PLA). It's great news if you want to make casting molds - but not so great if you want to directly fabricate durable parts.
2) There is no gradual progression from the familiar FDM extruders to SLS, SLA, and similar technologies that produce high-accuracy parts or can work in metals. These technologies are inherently messy and have other surprising trade-offs, and are suited chiefly for very dedicated hobbyists and for quasi-industrial applications.
1) Not true. The resolution and printed parts in ABS and PLA are essentially identical. The only reason you see a switch from ABS is that PLA doesn't require a heated build bed and companies like Makerbot are trying to simplify things to make them cheaper and more plug and play for mom and pop.
2) Why does there need to be a progression from FDM to SLS and SLA? The progression is there on the software side with things like slicing, 3d modeling, etc. There isn't a progression from inkjet to laser printers, but that didn't stop anything.
1) The improvements in the output of FDM printers is in good part due to switching to lower-strength materials (e.g., ABS -> PLA). It's great news if you want to make casting molds - but not so great if you want to directly fabricate durable parts.
2) There is no gradual progression from the familiar FDM extruders to SLS, SLA, and similar technologies that produce high-accuracy parts or can work in metals. These technologies are inherently messy and have other surprising trade-offs, and are suited chiefly for very dedicated hobbyists and for quasi-industrial applications.