I doubt it ever will (worldwide I mean). In some countries it will make headway. But in countries where there is already a form of full contact football (ie rugby union, rugby league, or australian rules) it will be a lot harder (and possibly impossible) to catch on.
Take, for example, how rugby union is doing in the US. Despite being a very different game the simple fact that it appears to rival American football has made it nearly impossible for rugby to gain a good strong support base (not that its support base is wimpy it's just too small).
Until people can realize that each type of football (rugby union, rugby league, AFL (australian rules not arena), association/soccer, American, gaelic, etc) is really an entirely unique game that has its own pros and cons, it will be very hard for them to coexist.