I really do not see how the European Union can survive as a entity. There are not enough checks and balances in the system. It is not really a country but a club that tries to interfere in the governments of it's members. The weaker countries will chafe under the bumbling micro management of their internal affairs by the stronger nations.
This is a terribly complicated process, made more complicated by the fact that the larger states don't want to surrender sovereignty unless they have guarantees of control of the whole works. Imagine if you will that thirteen independent states tried to do that, say, over 200 years ago, and had not had leaders of such ability.