This is the most depressing segment I've ever seen on Comedy Central. Krugman looks even sadder than usual, and his sigh at the 2:45 mark regarding profit reports at Goldman Sachs speaks volumes.
As usual, Stephen Colbert illustrates the right wing naysayers perfectly, to paraphrase: "Ten percent of the stimulus money is spent, which means it's a one hundred percent failure. If I have a fever, and I'm not better after one penicillin pill, I'm back to the leeches."