Interacting with tinymce in wp is possible:
because tinymce is a default editor
(plugin I developed for downloading offers from shoppydoo, a price comparator service: http://www.shoppydoo.it/ )
The extension generate a tag that will be parsed and recognized by the backend plugin, replacing it with a parsed xml coming from price comparator service. Revenues are accredited to the editor/owner of the blog (need an account on shoppydoo).