Can the EU become a superpower like the U.S.?

For Europe to become military power it needs to unify its member states armed forces and foreign policy.
At some time Russia may become part of EU. This would make EU into a huge power.

Personally, I think that power resides in economy. Any state that experiences economic decline will also experience military decline as well.

Originally posted by Genghis I doubt Russia would join the EU, and if they did, I think that would create two rival camps, Russia and Western Europe, and it would eventually schism.

Not necessarily. Europe, outside of Russia, is more powerful economically and has larger population. Also, Russia would have to conform to EU constitution.
A very large EU, including Turkey, could absorb Russia. Don't forget that Germany had a bit of the same problem. A visionary like Adenauer, saw EU as a way of neutralizing German dominance in Europe in a positive way.