Usually it starts in the EU. Last time the SIII got the update for 4.1.2 Jelly Bean it was Poland. Within 6 weeks everybody else in the EU got it. The US s month later.
Exception to this rule was Jay. He had it long before Poland. So, the moral of the story is: if you want it quick, move to some one-horse town in the US. Move close to where the Cooley Clan have settled.