On October 7, 2008, the Federal Reserve further expanded the collateral it will loan against to include commercial paper .

http://en.wikipedia.org/wiki/Federal_Reserve_System#cite_note-91

Commercial Paper Funding Facility

On October 7, 2008, the Federal Reserve further expanded the collateral it will loan against to include commercial paper using the new Commercial Paper Funding Facility (CPFF). The action made the Fed a crucial source of credit for non-financial businesses in addition to commercial banks and investment firms. Fed officials said they'll buy as much of the debt as necessary to get the market functioning again. They refused to say how much that might be, but they noted that around $1.3 trillion worth of commercial paper would qualify.