This mention of “Webmentions” by Drew McLellan caught my attention. Webmention is a W3C Recommendation and similar in concept to Pingbacks. (It also seems adapted to deal with some of Pingback's weaknesses.)
I'll admit not hearing about Webmentions until I read Drew's post. There's at least one WordPress plugin you can install to try out Webmentions. I don't know if this will take off, but in a world where blogs are closing their comment sections and people are investing their time on social media, it's a worthwhile project.