Companies like Colnago were investing in R&D do make the better steel frames in the 80's. They're now just trying to replicate the classic lines.
How many new alloys have been released in the last decade? 4130 is big in the utility bikes.
Perhaps a bit more new stuff in stainless lines...
Cycling has borrowed from other fields such as aviation, but even that may be reducing the reliance on steel as a structural component.
I have no doubt some steel manufacturers will be improving technology... hydroforming? More mandrel forming? But, the industry as a whole has peaked.
Perhaps one of the problems is that he market as a whole has been saturated with JUNK. And most of the gems have moved to other materials.
Nonetheless, there are a few manufactures such as Bike Friday which still use primarily steel, and continue to innovate.