Huffpo's piece on Sarah Palin being booed by disappointed autograph seekers in Indiana has amassed almost 15,000 comments. You have to look at the front-page right sidebar for that number, but there are 285 pages of them (mostly supportive of Palin, natch). I'll leave it to others to assess the possible political implications. Fifteen thousand. Don't believe I've ever seen even 2,000 anywhere else, including LGF back in the day.
Update: Oops, I see that Huffpo itself apparently routinely gets several thousand comments on individual posts. But still.