I bought most of their second response, yet I still think their Excel error was dumb. Besides, if it were 2.2% rather than the eye-dazzling -0.1%, I would doubt they could ever publish it in the first place. Although Reinhart and Rogoff referred to their JEP piece where they've shown similar results of negative correlations, I still believe what really caught the eyes of economists as well as politicians was the magnitude of that correlation, particularly when the debt-to-GDP ratio passes the 90% threshold.
Interestingly, adding new flavor to this debate is neither economists (see here and here) nor politicians but comedian host Stephen Colbert. He took on this debate yesterday and turned it into something hilarious, something epic. He brought onto the stage one of the critics from UMass, an econ grad student Thomas Herndon, and shouted at these "left-leaning academi-aholes", "nerds! I bet you found them [the errors] on a Friday night with your mom, while the rest of us were going up to The Point and drinking PBR!"