In my browser (Minefield, Firefox 3a1, Gecko/20061214) the font used in the "blog of the minute" section is very hard to read. Not sure whether that's a WordPress.com or Minefield issue though.
Update: I just viewed WordPress.com in IE6 and the font is the same there… strange.
Update 2: Matt Thomas requested a screenshot of it. The rest of you can see a screenshot of it here. Just click the thumbnail below.
Update 3: Problem solved! After an e-mail from Matt I tried to change the font smoothing in Windows XP from standard to ClearType. And that did it! Still, this is the first web page, that I have discovered this. But now it is readable, and that's the most important thing :-) – thumbnail below.