The House of Representatives is expected to vote as early as today on a sweeping housing bill that would expand FHA loan guarantee programs by $300 billion and grant the Bush administration's request for authority to provide a capital backstop for mortgage financers Fannie Mae and Freddie Mac. The Congressional Budget Office estimates that while there's only a 50-50 chance that Fannie and Freddie will require a government bailout, the price tag could be $25 billion if they do (see story). Sen. Richard Shelby, R-Ala., called the CBO estimate "pretty good news," Reuters reported. In a speech Tuesday, Treasury Secretary Henry Paulson said that Fannie and Freddie's ability to continue guaranteeing and purchasing mortgages "is central to the speed with which we emerg...