CNN reports:

Treasury Secretary Henry Paulson said the Bush administration plans to ask Congress to enact legislation to temporarily increase the line of credit that the companies have with the Treasury. It would also allow the Treasury to buy stock in the companies.

Paulson also said the Federal Reserve should be given a greater role supervising the finances of Fannie and Freddie.

In addition, the Federal Reserve announced Sunday that the mortgage finance companies can turn to the Federal Reserve Bank of New York for funds. The move gives Fannie and Freddie the same access to the funds as commercial banks and Wall Street firms. The agency granted investment banks such access earlier this year in the wake of a similar crisis of confidence when investors lost faith in Bear Stearns

So, how bad with this affect the national debt?

I'm sure analysis to follow but you can bet they wouldn't be doing this if the two GSEs were healthy.