David Rosenberg warns don't take Euro's longevity for granted:
Greece today may well be the touch-off point for market instability just as Thailand was back in July 1997 — who would have thought a Baht devaluation would have touched off a major Asian financial crisis. Then again, who thought the subprime mortgage market would unleash a broad credit collapse — certainly not the folks at the Federal Reserve. And, as for the Euroland, don’t take its longevity for granted either. Go back to the history books and read about how long other currency unions lasted in that part of the world in the past (like the Latin Monetary Union circa 1867 or the Scandinavian Monetary Union circa 1873).
Maybe it's too early to be too much worried about Euro, but be reminded that the fate of Euro had always been a jousting between two of my favorite economists, Milton Friedman and Bob Mundell.
***Read this classic historical debate*** at University of Chicago between the two great minds.