i recon for barrels, we will be looking at something like the apex/flatline, putting some kind of spin on the ball to make it shoot further, but having it so it is more compact and more accurate
for loaders, something faster isnt really needed, something ligher could be seen in the furture, or a loader that doesnt need batteries, maybe an internal pack with a charger (thus reducing weight and size)
for guns, who knows, faster again isnt really needed, something that hasnt been tried before could be an idea, but we need to find it first lol
for air, i have no idea, the only thing i can think of is better compressers that can do more than 4500psi, thus letting bottles get smaller and lighter
for paintball in general, i see the woodlands being used abit more but thats me