Thinking about Linking

I often want to respond to a comment thread on another site at greater length than would be appropriate for a reply comment, or in such a manner that it would derail the original discussion. But often people say things in comments that they might not say in a front-page post (I certainly have) and so I refrain. Of course, we don't need permission to link to anyone, but what do you think of promoting a comment to post-status elsewhere?