I just noticed that Mudbytes has a post self-deletion button now (:surprised:). I'm curious: Does it only work on individual posts, or can it vaporize a thread as well (so long as no replies have been posted to it)?
After you posted, Igabod, I decided to see if I could create a forum causality violaton (delete my post, then reply to your reply with the original post) since it is still showing the delete button even though a reply exists. Unfortunately, it failed; answering my original question.
There is something of a gentleman's agreement to not edit (and hence certainly not delete) posts after people have started replying to them. (Excepting of course fixing mistakes, etc.) It can be extremely confusing for people who visit the thread later. That is in part why there has been some resistance to the ability to delete/edit posts. Personally I think it's a good thing to not be able to delete the first post in a thread – if a thread was created by accident (e.g. double-post), it's ok to say so and have the admins delete it.
Actually that button has been around now for awhile. I don't remember exactly when I added it. There's a time limit in place on how long the button remains available. Right now it's at a generous 6 hours and has so far been doing just fine there. After the time expires you cannot edit or delete a post.