Well, I finally got around to nuking that annoying ".pl" in the weblog's URLs - all the URLs should now not include it. Naturally, I've put a redirect from weblog.pl to weblog, so no links should break.
It took quite a bit of thinking, but it works - not showing file extensions is not one of IIS' strong points, however, it has more than enough power to do it if you know what you're doing. :-)
Please comment here if you find any bugs or other issues with this change, or indeed any part of the weblog system.