Awesome to see the excitement so far!
@Ray, it's very possible we'll support inline comments in the future, but I'm not 100% sure right now. I plan for us to try the “separate community” direction at first, where it's more of a social space than classic blog comments. Then I hope that'll reveal what makes the most sense, as far as embedding comments on blogs themselves (“inviting someone to write on your wall”). I imagine it'll definitely be important for sites that are more standalone destinations / need more independence from our little network.
Otherwise, Webmentions are 100% on the roadmap. End goal is that this works with the fediverse, across independent sites, anywhere on the web, etc. You can find some of my general thoughts here: #comments