Two tier Euro? Germany and friends become Euro 1 and the rest devalue to Euro 2.

Plan A was "defend the Euro at all costs".

Hans-Olaf Henkel

Plan B is for Greece and maybe others to drop out of the Euro.  From Hans-Olaf Henkel writing in Financial Times and quoted by Global Economic Analysis comes Plan C:

"That is why we need a plan “C”: Austria, Finland, Germany and the Netherlands to leave the eurozone and create a new currency leaving the euro where it is. If planned and executed carefully, it could do the trick: a lower valued euro would improve the competitiveness of the remaining countries and stimulate their growth. In contrast, exports out of the “northern” countries would be affected but they would have lower inflation. Some non-euro countries would probably join this monetary union. Depending on performance, a flexible membership between the two unions should be possible".

The Global Economic Analysis link has red meat and applies the principle: "Never believe something until it has been officially denied".

Added: "A clear majority (60%) of Germans no longer sees any benefits to being part of the Eurozone, given all the risks, according to a poll published September 16. .... If the government wanted to establish a transfer union, it should discuss that with the German voters, they demanded, because it would be a fundamental change in the E.U. constitution and should be legitimized by vote. Otherwise, Germany would be "threatened by a populist movement to exit the E.U."  Bailout Rebellion in Germany Heats Up
with h/t to Mish Shedlock.