Buffet, as well as John Boggle (inventor of the S&P 500 index fund at Vanguard), are both suggesting that now's a great time to put additional money into the market.
My original "pop quiz" introduces a complication: we're clearly in a recession, and there's some evidence of deflationary prices (i.e., a vicious falling demand leading to falling salaries, layoffs, and falling prices). However, many of the possible fixes being contemplated involve spending an awfully large amount of money. Money that we don't have. That means the U.S. can either just print more money (= inflationary, effectively devaluing the dollars in all of our pockets) or borrow more money (at higher and higher rates in order to attract buyers for the less and less attractive bonds, forcing higher taxes to pay the bills, and thus creating recessionary pressures).
Holding currency (or money markets) over the past two months has been the only winning strategy. Everything else, except maybe gold, has been falling through the floor. The part that seemingly nobody expected was that there would be a "flight to quality" when the bubble popped and "quality" would be defined as the U.S. dollar. If the flight had gone elsewhere (the euro?), things would have turned out quite differently.
That said, the stock market is quite attractive these days. Likewise, if you have the stomach for junk bonds (e.g., debt from GM), the interest rates are nothing short of spectacular -- but you'd be a fool to loan money to some of these firms.