Considering the Eurozone is comprised of a mishmash of nations who have been warring with each other throughout the whole of recorded history -- and before -- it's a miracle that they managed this kind of unity at all.
But manage it they did, and the advantages are so great that I think they'll throw all their resources behind it to make sure it stands.
Greece may withdraw. Portugal, Spain and Italy are on shaky ground but will probably manage to salvage their economies. But I think the Union, and the Eurozone will survive. I hope so.