Here are the stats for January at my company’s website (using FastStats):
Internet Explorer 6: 81%
Internet Explorer 5: 8%
Firefox: 7.7%
If you haven’t checked your site in Firefox yet…you better. The borders of the tables in mine look different and the font-size is smaller, but everything else seems to work. (A couple months ago, you may recall, I had to fix the guestbook form to work in Firefox.)