Robert_Charlton - 6:11 pm on Mar 17, 2012 (gmt 0)
these would only concern me if i preferred not to expose the contents of comments to visitors.
Along the same lines... having to do with concerns about exposing comments to humans (as opposed to Google's indexing)... I've occasionally had clients who (prior to my involvement) have made references to seo strategy in their comment tags, as in: "page for seo", "heading for seo", "text for seo", "links for seo", etc.
Apart from the fact that I don't think that seo strategy can be grafted onto a site this way, this kind of exposure, IMO, is not a good idea. ;)