As of right now:
The Hulk (well, Banner and his new team) is in the New Mexico.
Scarlet Spider is in Houston.
Guardians of the Galaxy are not on earth.
Nova as well.
Gambit has been all over the globe in his series.
Cyclops' team is in Canada.
Savage Wolverine takes place in the Savage Land.
Captain America takes place in another dimension!
What books are you reading? To me, the majority are NOT in New York at the moment.
Sure, that's where the Avengers meet. But that's where their HQ is. Their first arc took place on Mars!