The Federal Reserve's sudden return to "accommodative" dovishness in response to the stock market's swoon telegraphs its intent to fire up QE once the recession kicks into gear. QE (quantitative easing) are monetary policies designed to ease borrowing and the issuance of credit, and to prop up assets such as stocks and real estate.
The basic idea is that the Fed creates currency out of thin air and uses the new money to buy Treasury bonds and other assets. This injects fresh money into the financial system and lowers the yield on Treasury bonds, as the Fed will buy bonds at near-zero yield or even less than zero in pursuit of its policy goals of goosing assets higher and increasing borrowing/spending.
This is pretty much the Fed's only lever, and it pulls this lever at any sign of weakness in stocks or the economy. That sets up an obvious question that few seem to ask: what happens when QE fails? What happens when the Fed launches QE and stocks fall as punters realize the rally is over? What happens when lowering interest rates doesn't spark more borrowing?