You are all right and all wrong in the same time.

Out from UK, the price will not be very much different.

But from EU, the price will eventually even out. The reason is banks in Italy is in crisis, banks in Germany is suffering, banks in Portugal is on life support, banks in Greece are already zombie...Eventually, Pounds will recover and be strong while Euro tanks. I think US bound flight will be slightly more expensive but flights to Asia will remain competitive.