The banks that hold these mortgage portfolios were forced to write down the portfolios by marking them to market. In some cases that mark to market was as low as 13 c on the dollar
Lets use 30 c on the dollar for this example
the government buys the loans from the nak at 3 c on the dollar
Within those portfolios are an array of different types of mortgages
They are all tied to an asset a home
Lets say siomeone paid 500k for a home and is foreclosed on and the house sells for 250k after all fees
that is 50 c on the dollar on a loan they paid 30c for and on that loan the government makes a profit.
Bottom line is that none of the loans will be worthless as again there is an asset attached to them
My opinion is the government will make $ on this bailout. Hopefully they will contribute the gains to the consumers benefit in some way like possibbly paying down the deficit