Since the Dutch just hosted the baseball worldchampionship it's not quite hard to find some info on that.
Below are some countries that entered;
Cuba, the Netherlands, Australia, China, Taipei, Columbia, Greece, Japan, Nicaragua, Panama, Spain, South Africa, South Korea, Sweden, US, Canada
Countries which not entered the competition;
Aruba, Puerto Rico, Brazill, Italy, Nigeria, Great Britain, Tjech, Oceanië (don't know how to translate that one :S)
25 so far, it shouldn't be that hard to come up with 50 other (without using all 50 US states
)
Besides I always had the impression that the IOC favoured france not the states.
I don't think that finding 75 countries in which paintball is being played is a problem, nor is finding women who play. The real challenge is how to get them all to agree on a standard format, a basic set of rules and to unite them in 1 federation.
So if everyone works really hard perhaps it can be pulled of in time for the olympics of 2020?