Localization is now possible for Edit Author Slug 0.3+. Ideally, this would have been possible from the beginning, but I was lazy. I’ve included a file — edit-author-slug.pot — which can act as a template for your localized po/mo files. Contact details are in the file, so if you decide to translate the plugin, just send me the files, and a note with the language you’re translating, and I’ll get them added in an update.