Not so fast.
The banks that loaned Greece that money rely on Greek bonds retaining their value in order to claim the reserves they need to loan money to businesses and to pay out money to depositors at the ATM. Now that the Greek bonds are cut in half, they need to restore their reserves from somewhere. Where are they going to get that cash? Well, the European Financial Stability Facility (EFSF) is going to provide that. And where does the EFSF get that money? It borrows it.
In effect, the obligation for the Greek debt has gone from Greece to the banks to the EFSF. EFSF debt is serviced by ... members of the EU ... who can't pay their bills now. The real backstop to this is the European Central Bank which can print money.
Guess who's going to end up paying the tab and how they're going to do it.