It was brought up in a comment-block under a recent question that the practice of deleting comments that are (or have the potential of becoming) actual answers is potentially troubling to commenters.
Is there a consistent and defensible rubric concerning how close a comment is to being an answer that causes it to be removed? Is/should there be a waiting period before deletion?
[Note: I don't care much one way or the other. To me it was the mildest of inconveniences to have a comment deleted, but it sounded like maybe there was more to say on the matter.]