I’ve implemented something resembling threaded comments here, which means that you can reply to specific comments previously posted on an entry. Each comment now has a small ‘reply’ link next to it – clicking that will let you post a response to that comment.
It’s not true comment threading since the comments are still displayed in a flat form, but it should be easier to monitor discussions now. The legwork is done by Arvind’s Simply Threaded plugin for Movable Type, which is in beta (but not readily available), and it’s supposed to resemble the comment structure on Vox.
Go on, have some fun with it.