Football already dominates America. This much is is known. But while the power brokers behind the sport must figure out a way to maintain the sports relevancy (so it doesn't fall off a cliff like baseball). Admittedly the game has nothing but room to grow overseas and in other countries.
I compare it to soccer in America. And sure, while there will always be a vocal "OMG WHO ARE THESE FAIRY CHILDREN RUNNING AROUND IN THIS FIELD KICKING A ROUND BALL AROUND OMG FOREIGNERS" minority in America, the game has grown exponentially even since I was a fairy child kicking a round ball around a field in the nineties.
I know this will be hard for some people over 30 to stomach, but soccer is already quite the relevant sport for people under the age of 30. With the expansion of internet streams and HDTVs and broadcasting rights, soccer will continue it's ridiculous rate of growth well into the foreseeable future.
As the talent level and coaching schemes in American football reach new heights, the smart coach will turn to international wires to find undiscovered, talented gems. It has already happened to a degree. Everybody knows about Brad Wing, LSU's Australian punter Brad Wing, or the Dutch players responsible for Boise State's "Couch-gate", or even the Russian sumo wrestler (those exist!?!?) that USF just signed.
I hope this is a sign of things to come and not a fad. One thing I like about soccer is the international aspect. I like watching club teams featuring players from three continents. While it's awesome Ohio State's talent bedrock is in Ohio (unlike.... let's say Michigan, who also has to recruit in Ohio to field a competitive team), I think it would certainly be cool to bring in players from the Netherlands, Russia, or even Australia.
As the game expands, international coaching will catch up to its American peers, and the talent gap will begin to close, much like international basketball has closed the gap with American talent. While I'd like to think America will always dominate football, the world is certainly producing more athletes than America, and I guess it's impossible to prognosticate these things fifty years down the road. I don't care if fifty years from now Ohio State is composed of Chinese mutants, so long as they beat the second-rate Chinese mutants who play for Michigan.)
Maybe I'm wrong, maybe neuroscience will continue to shed light on what a chronically debilitating game football is and it will go the way of boxing in that American athletes shy away from the sport, but I am fairly confident we will continue to see more international flavor added to the sport.
Some will revile this, much like a too large portion of this country reviled African-American athletes encroaching on the "purity" of their sport in the middle of the twentieth century and international ones doing the same in the latter portions of it, but I think it would be pretty damn cool to see. Plus, there are branding opportunities abound overseas, and even more broadcasting rights to sell. You'd have to think the institutions of this sport would be down with this idea too.