It turns out that relative rate of appreciation or depreciation with respect to other assets is also very important.
Denominating debts in bitcoin seems to have led to a lot of disasters, simply because bitcoin has tended to appreciate so fast that it is hard for anything, even dividends paid out by publicly held companies, to keep up with it.
Fortunately for debtors, alternatives exist.
General Financial Corp for example has managed to refinance a number of debtors by offering (secured) loans denominated in DeVCoin.
-MarkM-