Holders and users of the USD will feel less pain due to world currency status. Euro and others are close behind. Debts don't unravel all at once but in a chain reaction. How fast could it reach the American homeowner, that's usually the only question people worry about.
The PIIGS go down the tube first and when that happens the rest of the world will follow with the U.S. being last unless Commie China takes over as the World Currency. If that happens the U.S. will be next to last. My WAG.
It's being implemented in Argentina, first attempt was not successful, but they are consolidating power with a new President - Patagonia for debt relief. In America, it will be Federal Land for debt relief - the massive Federal Debt and Deficits are not without intentions.