The $700 billion is a drop in the bucket, a pebble thrown into a churning ocean. This thing is going to cost many trillions. The Fed is now buying commercial paper and the commercial debt market is showing signs of life, but banks are all still terrified to lend to anybody else. Until we find out where the bodies are buried (may take years) that'll be the case. Until then the central banks will have to do everything, from guaranteeing commercial debt to effectively nationalising the banking industry in their respective countries. I'm still fairly confident that we'll avoid Armageddon but it's still a distinct possibility. The best-case scenario right now is a year to ten of recession, sluggish growth, economic contraction etc., while the global banking system deleverages and indivisual banks write off/pay down their debt/go out of business.