And this one explains just how much of the world economy has the same problem.
http://krugman.blogs.nytimes.com/2010/03/17/how-much-of-the-world-is-in-a-liquidity-trap/
Companies are hoarding and not employing because unused money is increasing its value (ie deflation) relative to other assets. The Fed is trying to get people to think this isn't such a good idea. So they promise low interest rates, print fresh money (QE) etc.
We're in a trap created by excess responsibility.
Philosophically, this is great fun. Practically-speaking, it sucks. It would be much better if companies put their money to work instead of improving their balance sheets further.
Reading folks like ktc or listening to Republicans, the Fed's policy appears to be working a little bit.