Gamecenter should work in maybe not all but a bunch of countries. The biggest issue lies within owning the rights for NHL in the specific country.
Here in Sweden (and the other nordic countries I think), a certain network owns the right to show NHL games and they put it together with a golf/soccer/whatever package and charge like $45 bucks a month when all I want to see that they own rights to is NHL. On top of that, I don't think you can re-watch games, you have to catch them live... stream or on TV, doesn't matter. No surprise people pay for hockey streams .com or go with that LazyMan computer program.