Privacy should be covered because the comment count is visible to anyone who can see the entry, so the same settings would apply as for locked entries already.

Are there existing standards for linking to comments on RSS feeds and/or displaying the comment count? If there are, we should use those, but otherwise, yes, the comment count would be good. Would it display as a new entry in someone's RSS reader every time the comment count changes, or would it just be a change to the existing entry?