What could possibly go wrong?

The crisis of the eurozone: what’s caused it, what’s happening, what’s going to happen? How has the media fared in describing the crisis and the way(s) to overcome it? Consider the widespread enthusiasm with which the media greeted the introduction of the euro a mere 10 years ago. By eliminating national currencies a de facto system of Gold-Standard-like fixed exchange rates between sovereign states as economically and culturally diverse as Finland and Greece was created, without an effective means of ensuring adherence to a set of rules on the conduct of national fiscal policy, with no major policy instrument other than salary deflation available for relatively poorly performing member states to address a loss of competitiveness, and with one single interest rate to cater to a wide range of fluctuating, but not necessarily directly correlated, national economic circumstances. What could possibly go wrong?

Background reading on a hypothetical shock announcement early one Saturday morning in Brussels and Berlin at some indeterminate point in the future. X marks the spot.