The search engines have jointly announced they'll be supporting a microdata vocabulary, schema.org. For Google, this seemingly supersedes their prior support for RDFa and microformats (which, for the time being, Google will continue to support); for Bing this is their first formal foray into structured data markup. Did the search engines make the right decision? With vocabulary lock-in and lack of extensibility, do the flaws of a microdata format outweigh it's possible widespread adoption? Should web publishers continue to markup documents with RDFa or microformats, even though Bing doesn't support the language? So how about a summer meetup to discuss and debate?!
This is a joint event with the SEO meetup group: http://www.meetup.com/VancouverSEM/events/26788461/