Yep it depends for whom.
All this Greece nonsense lead to the devaluation of the Euro, so it's bad for Europe. And probably good for the US.
When it goes vice-versa, it's the same.
Greece is now in the process of losing its independence to Germany and France, Italy and Portugal will follow its lead. Devaluation of Euro is the price the European population has to pay for stronger unification in the future.
Portugal already has the Troika aid, I don't think Spain will have it, they're actually recovering.
I think in the end it will be Germany to leave the euro. Once again, they're just more efficient than the rest of Europe...
How can they leave the eurozone, if it was their idea in the first place? In fact, the United Europe has been their dream for at least a century already (actually, this dream has its roots as back in the past as the Holy Roman Empire). The euro is only a means for making this dream come true (they failed miserably twice to do just that through military in the 20th century).