In America, we have Theravada, Vajrayana and all the other Mahayana traditions represented pretty well, as far as I'm aware. My two cents is to leave it at that. Personally, I like how there's a choice here. If you want Theravada, it's here. You don't have to go to Sri Lanka or Thailand anymore. If you want Mahayana, you don't have to go to those countries. It's all here. Maybe that IS the American Buddhism - having a choice of which tradition the individual wants to follow.