While I do think you’re right about the awfulness of that particular combination, your own site is somewhat tiring to read long posts on as well. Why is the font size set to 80%? That’s small enough to make it unnecessarily tiring to read (for me, on my particular browser, at least). Is there a reason why your text needs to be smaller than the browser’s default size?
Also, you use a slightly grayish tone for your text. Why? Black creates a much better contrast. Example: compare the line “Posted by Jeff Atwood at December 19, 2006 10:23 PM” to the rest of the text in your post. This problem is worse in comments, where the background is gray(er) than the main page.
Oh, and I’m not really complaining, I normally use RSS for reading your excellent blog anyway, so these issues seldom bother me. You might want to think about them though.