The interweb is awash with rumours of the re-introduction of the Deutschmark this morning. It sounds rather unlikely, but the German people would love it if Angela Merkel just stood up and said, "The euro's not working; we're going back to the DM."
I wonder if the Germans have secretly printed up a completely new currency set, just in case.
It would not be unprecedented. The Swiss have already stockpiled a new currency ready to roll out with little notice in case the CHF suddenly loses credibility.