The last thing the EU needs at the moment is more members, it's deadlocked most of the time anyway! not to mention the lol fail they keep producing
More members aren't needed at the moment, that's right. Because no one wants to discuss which way the EU should take:
A loose Federation or a Union.
Sounds familiar to the Americans from the United Staates, right ?

Time for the Europeans to read the Federalist Papers...
But while most Europeans would tell what the USA needs a strong Central Government and a centralized Social Security System, it would be the last what they wish for the EU

A more realistic view of the future would be a more bilateral approach to European Integration instead of new members.
The Swiss Confederation isn't part of the EU, but has negotiated to participate in some Areas with and from the EU. Mainly in the sector of free trade.
Geographically the EU doesn't need no new members after Serbia. With removing of border procedures travel and commerce with Eastern Europe would be a lot easier if Serbia would become a member of the EU or at least a member of the Trade Union.