Was thinking about how to fetch Webmentions and I think that this approach is not only fantastic (obviously biased, lol) but now once more implementations pick this up, static sites can provide a feed of their Webmentions with one line! That's truly my hope—to be able to query Webmentions (and subscribe to them) so people can see reactions to things in their social reader. An intelligent reader could filter out some of those replies (from undesired sources) and still give a relatively healthy experience.