in reply to Give Maintainer Permissions to delete their own nodes?
I imagine that you'd have to put limitations on it, such as once there was a reply to that node, it couldn't be deleted. Doing so (besides making database maintainence more of a hassel) would distort the flow of the thread.
'course, if it's not a root node, you can always change the text to 'I humble myself before my fellow monks, and have changed this comment to attempt to reduce my apparent ignorance to my brethren'.
I've even wondered (to myself) about the validity of editing a node once it's had a reply to it. It could really change the karma.