I personally tend to focus on development of high efficiency designs because I prefer the sound of low-powered amps, particularly certain tube amps. In that realm, there have certainly been some recent developments/refinement of drivers that I would consider major improvements. I like what is being done with full/wide range drivers, like the 8” AER BD series, Voxativ drivers, etc. Although the basic technology is not new, I am sure that modern technology played a big role in refining the design. In recent years I have heard several very good systems employing such drivers (e.g. Charney single driver systems, Voxativ single and multiway systems, Songer single and multiway systems).
At the Capital Audiofest, I heard Andrew Jones talking about his design of the Mo-Fi speaker that is getting very favorable notice (I think it is very good for the money). While the basic design of the co-axial drivers is old school—paper cones, pleated surround, silk dome tweeter—the way it was designed employed modern technology, such as using 3D printing of prototype parts. It would have been pretty hard to get to the low price point of these speakers without modern design tools.