For a true global and distributed RSS community, today's main reader platforms could join to create a standard protocol for comment sharing.

This would enable them to "integrate" the comments for news items; for example: user A uses The Old Reader, and posts a comment on a news item (some slashdot article); user B, who uses Inoreader, when seeing this same news item in his viewer, is able to see the comments from user A, and to reply to them; the reply would also be visible in user A's feed.