One reason some Krugman posts are both useful and inevitable on HN: he's been right about a lot of important things a lot more often than he's been wrong.
It would be really interesting to see a list of posts where he's been right as well as a list where he's been wrong. In fact, it would be great if there was a site that hand a right and wrong list for all the major economic and foreign policy pundits in order to see some accountability.