I saw this in a recent David Wessel article:
In January, the [Congressional Budget Office] pegged the ultimate cost to taxpayers of the $700 billion TARP at $189 billion. When the agency issued revised numbers in late March, it revised that to $356 billion, a change that drew little attention. The larger estimate reflects, among other things, the Treasury's move to use the TARP to help avoid foreclosures, as well as the changing details of its aid to American International Group Inc., and the deterioration of financial conditions and of banks in which the Treasury has invested TARP money.
In light of all the bailout furor, it's remarkable how little play this revision has received.