It's pretty clear that you're looking for a reply that involves new technology. However one current trend that I see continuing involves the widespread use of black powder guns and the technology that involves the original gun powder (black powder) and its substitutes.
Literally millions of cap & ball revolvers are being sold world wide that are reproductions of mostly U.S. Civil War era technology. These are mostly made by Italian outfits and can be outfitted with cartridge conversion cylinders in various compatible calibers with hardly any Federal restrictions in the U.S..
In many European nations these are the guns of choice for competition and recreational shooting. And now that the former Soviet Bloc countries are free they're having a resurgence of American western style cowboy action shooting, mostly with cap & ball revolvers. But they also have an affinity for Western single action six guns and muzzle loaders in general too.
So what were once 2nd tier nations are now catching up with what most of the 1st tier nations of the world allows with only very few restrictions.
Folks like to load their own black powder cartridges, or use lower pressure modern powders like Trail Boss etc...
Muzzle loading hunting with new inline rifle technology has also grown tremendously with new primer and ignition systems and powders, including a smokeless substitute powder and specialty inlines that use real smokeless rifle cartridge powders.
Some dedicated inline shooters have learned how to get better hunting and target performance from their single shots than they can develop with modern cartridge technology.
Regarding the growth of these forms of "retro" revolver and rifle shooting sports, many folks either totally or partially give up their centerfire guns in order to concentrate on what they enjoy shooting the most. And time and time again as folks grow older they often move into shooting black powder era guns and reproductions.
There's hundreds of models of muzzle loaders and black powder cartridge guns that folks love to collect and fire. Large numbers of dedicated people around the world reenact famous battles of their own country's black powder era wars on a regular basis just as we do in the U.S..
And since these types of guns are the most plentiful and least restricted in country after country, then it's clear that the future of old technology is continued growth.
And as the populations of developed countries keep growing older, the tradition of black powder shooting will never die out.
Some people legally make their own black powder at home. And since retired people have less disposal income, they would rather not spend as much money on centerfire ammunition either.
Cabela's sells tons of these guns and have built a small empire of multi-million dollar stores in the process.
Some folk own 5 - 10 or more cap & ball revolvers. And this is not just in the U.S. but world wide.
So while some parts of society look forward to new shooting technology, an ever growing segment of the population is looking backward, fueling the growth of old black powder technology being incorporated into even more new reproductions and models.