I think Greece secretly wants to leave the Euro as does, Italy, Spain, Portugal and Ireland. Unfortunately the design of the EuroZone does not take into account anyone wishing to leave so there is no mechanism to accomplish this. An analogy is of a hotel where you can stay as long as you want but cannot leave.
Virtually every comment or blog I read concerning Greece has some statement about Greece leaving the EuroZone. I suspect that Greece would not leave voluntarily and would wish to be pushed rather than to take a leap into the dark.
Despite all the rhetoric from the EU that it is stronger than in 2010, when all this originally came up, there are still a lot of unknowns as to what may happen if Greece or any other country leaves. The Euro, being a major world currency, could negatively influence other world currencies including the USD. The US is pushing the EU to make a deal with Greece come what may. The Greek government is standing up to the EU for once, demanding a better deal, rather then allowing itself to be steamrollered into whatever the EU serves up.
Lots of sabre rattling is going on but I think that finally, the EU will give in and go a long way to what the Greek government requires. Certainly reform is overdue, both in Greece and the EU. There are lots of things requiring fixing.