In the long run these differences will have to be reduced to achieve stability under a single currency. In the U.S., worker migration tends to equalize the disparity between regions. Such migration is fairly easy in a land with a common language, a single Constitution, and a national media. All these are missing in Euroland. Most Europeans are reluctant to move where the jobs are, even within their own countries.
Significant adjustments lie ahead under the new monetary union.
I wish them good luck, because they will need it.