....Will be regulated by the Federal Government.
For sure will be! The more advancements on slugs, higher pressures, etc the more dangerous and we all know what that means...
I don't believe so, at least not federal level perhaps manufacturer level to insure safety but advancements have been made in muzzleloader and they are still an open market and much more power. Local state laws can of course step in and in some states already has.
More advanced computerized regulators,
A uniform sizing on calibers,
On board electric pumps
Actual barrels rifled for Airgun speeds and projectiles.
Bullet design for low velocity penetration and wound expansion