A recent BBC News article has the U.K. "thinking" about adopting the Euro and dropping the Pound Sterling "because of the effects of the global credit crunch." Sounds like a bunch of politicians agitating for short-term gains and using "hindsight" to make their point. "Gee, if only we'd done that, we'd be better off today".
I say stick to your guns and your currency, because tomorrow you just may be better off in any case.
Otherwise, you first give up your money; political power is the next to wane (because you don't have your own money). Your influence is automatically diluted by being "one of many"; your best interests must now give way to the "good of the whole", which is to say, the powerful. Once your money and political power are compromised, borders become next to meaningless and military power is the next casualty (how are you going to pay the soldiers and to whom will they be loyal?). Finally, culture, religion, and law are all subsumed into the juggernaut; anything that stands in its way just gets crushed.
The EU operates through a hybrid system of intergovernmentalism and supranationalism. In certain areas it depends upon agreement between the member states. However, it also has supranational bodies, able to make decisions without unanimity between all national governments. Important institutions and bodies of the EU include the European Commission, the European Parliament, the Council of the European Union, the European Council, the European Court of Justice and the European Central Bank. EU citizens elect the Parliament every five years.
Maybe I'm just too "American" in my thinking; there is part of me that recoils at giving up sovereignty in whole or in part in exchange for a buck (or a Euro). But there is a very real undercurrent of raw power politics that comes into play. Sure, the EU is a powerful economic force, but it tends to run roughshod over the other elements of nation states. What started out as a good idea is quickly developing a Frankenstein life of its own.
The EU traces its origins to the European Coal and Steel Community formed among six countries in 1951 and the Treaty of Rome in 1957. Since then the EU has grown in size through the accession of new member states and has increased its powers by the addition of new policy areas to its remit.
Especially troubling to people of faith is the unremitting secularism of the EU, which simply reflects the growing secularism of its people.
The EU is a secular body with no formal connections to any religion and no mention of religion in any current or proposed treaty. Discussion over the draft texts of the European Constitution and later the Treaty of Lisbon included proposals to mention Christianity and/or God in the preamble of the text, but the idea faced opposition and was dropped.
In December of  European leaders signed the Lisbon Treaty which was intended to replace the earlier, failed European Constitution, which never came into force after being rejected by French and Dutch voters. However, uncertainty clouds the prospects of the Lisbon Treaty's coming into force as result of its rejection by Irish voters in June 2008.
The European Commissioner for the Internal Market Charlie McCreevy admitted he had not read the Treaty from cover to cover, and said "he would not expect any sane person to do so".
So, entire countries are expected to "just sign here" and never mind about the details? Yikes.
I wish I could give an actual analysis of the situation, instead of a knee-jerk reaction, but sometimes it's best to go with your gut: if it stinks, chances are something's rotten.