The development team at blizzard should give the option to play on EU/US/ASIA by one click for World of Warcraft and any other games that do not support it. You would have to buy the expansions packs to play on it for example: but, you should be able to switch via your profile instantly! 
. Today you have Starcraft 2 where you can instantly switch, same with Hearthstone!
This change would enable the ability to not have to make another profile to play on EU / Asia if you only have a US Account.