more than 1 in 25 people on a site like HN using IE6 would seem odd to me.. I'm not sure of anyone that would like this site and is still running ie6.
(on an assumption here that we're talking organic traffic - not SE results)
PG - want to give us the browser stats?
It's probable that the decision to stop caring about IE was made in light of similar stats. Note that he said he no longer concerns himself with IE, and that his stylesheet still contains IE-specific hacks. He's done nothing to intentionally dissuade any hypothetical IE users that might come along, and if IE's rendering gets worse over time, that only further justifies his decision to stop caring. On the other hand, if IE's rendering gets better over time, then not caring about IE won't be a problem because IE will render more like modern browsers.
It's also important to be clear that the site does look right. If simply not catering to one particular browser causes your site to be completely unusable in that browser, that's a strong indication that the browser vendor is incompetent.
Note, for example, that he tests his site against both Safari and Firefox, so we can assume he is not turning away those users. If his site attracted the "average" web surfer, one would expect roughly three times as many Firefox users as Safari users. But he actually attracting twice as many Safari users as Firefox. Since his non-IE traffic is so heavily skewed to Safari, it's not unimaginable that his IE traffic would be similarly skewed, regardless of any IE rendering problems.
As time goes on, IE market share continues to slip. This process is vastly accelerated in technical discussion and news sites.
I wasn't being sarcastic -- don't you think he's turning away his IE visitors by presenting a site that doesn't look right, and then turning around and claiming that IE is 4%?
Even for sites with a highly technical audience, that number is hard to believe.