It would start with a complete gutting of the transcon market. JFK-LAX, BOS-SEA, etc. Bascially connecting large coastal cities to others they already fly to. Once EK and every other foreign airline (including alliance and independent EU/Oz airlines among others) saturated those markets to oblivion they will then turn to other US markets. Obviously some will never be serviceable by 777/380's, but there are plenty that are. Its almost funny to see the so called LCC's cut themselves off at the knees in the future for some easy feed today. The bread and butter of JB/VX are the transcend routes. As soon as a dozen or two foreign widebodies from all the carriers can penetrate that little cabotage barrier, they will be flooded with red ink trying to survive long term.

But as long as the FA's are cute that makes it all worth while. Mr. Big Strong American Businessman must really be in a hurry to lose half his stuff.