The following link is to a blog, which does a very good job of summarizing the current situation in the commercial paper market.  The roll over situation is actually a bit worse than they state, as a lot of paper is being forced into over night duration.   

http://calculatedrisk.blogspot.com/2007/09/commercial-paper.html

Also, McCulley of Pimco wrote a very good piece on how this liquidity situation is cutting the wind of the "shadow banks".  His bottom line:  The Fed needs to cut, as a run on Wall Street will in fact hurt Main Street.  His supporting facts are in the letter. 

http://www.pimco.com/LeftNav/Featured+Market+Commentary/FF/2007/GCBF+August-+September+2007.htm