“Within our mandate, the ECB is ready to do whatever it takes to preserve the euro. Believe me, it will be enough.”
The ECB director was bluffing then. The ECB hasn't done anything special to save the euro. It wasn't even necessary to do anything. The euro was never under any threat at all. No country may be expelled from the eurozone against its will. No country has ever wished to leave the eurozone, too since it would take a lot of risk.
Thus, the euro has been perfectly stable even during the most dramatic moments of the European financial crisis.
Meanwhile, the eurozone stock markets (EMU) have significantly appreciated: