The semantic information is already in the selector that pops up, e.g. '.headline'. I don't see why they need to store anything elaborate to make that portable. The scope of the change (document, document type, section, site) isn't shown but presumably it defaults to 'type'.
BTW the in-place edit features remind me a lot of this[1] use of Deface[2] in Spree[3]
[1] http://www.youtube.com/watch?v=qjgQHzYcxIQ