TheWikiEditButton.org

Why not be more ambitious and call it simply "THE wiki edit button" (e.g, "In order to have the wiki button you need to install the extension"). The "universal edit button" perspective may only be appropriate for people who know that there are many wikis and wiki engines, that is people in the know. Most people don't...

The story should include something along the lines of "wikis want you to edit them", I think. That's the "why" part of the story: the button is an invitation to users to edit the page. "If the button shows up - you know that you are invited to edit the page". "Don't worry - you can't break it" should be in there somewhere as well.