For those that have been keeping an eye on the new wiki you may have noticed a couple of things change recently.
First anonymous editing has been disabled, so you have to login to the wiki in order to contribute.
Second the URLs are in wikipedia style format, so articles can be accessed like http://wiki.lesswrong.com/wiki/Utilon instead of http://wiki.lesswrong.com/mediawiki/index.php?title=Utilon (the second form still works of course)
This has now been fixed.
Comments now correctly follow the Post they belong to and you can reply to them :)