I don't believe we'll ever pay our debt, at least not in the conventional way typical individuals/organizations pay their debt. It's simply too large to pay off and it will take 100 years of austerity measures, massive cuts to entitlements, the military, coupled with huge tax hikes. That will never happen, you can look back 20 years from now and you'll remember someone on some real estate message board said so.
What might happen though, and what would fit under the "unconventional" means, is for the Fed to inflate our way out of it - think about paying off a trillion dollar of debt in what's equivalent to $100 billion today, it's happened at some countries in the past and I fear we're on that path. There's also the possibility, and I know many people think it's unimaginable right now, is that the developed world total debt will become so huge that the powers that be decide to wipe everyone's slate clear, and declare a single, new currency.
As far as people like us are concerned, I think we should be okay if either scenario occurs - we own hard assets and people will always need a place to live, and they'll have to pay for it whether it's dollars, gold, or the new world currency. If inflation sets in, those with leveraged and mortgaged properties will pay for it with cheaper dollars, if there's a depression and deflation happens, then God help us all.