A note for the translators: Please change the tag from "untranslated" to "translation_available" when you finish up a translation request. I know I'm guilty of forgetting to do it sometimes as well, but it does makes it easier to look through for future translations.
I agree with untranslated staying as well. The way it seems to work is, if a picture when initially posted has Japanese (Non-English) text, it's untranslated. When someone translates the image and posts it into the comments thread, translation_available is added. When the image gets edited to include the English version, the original becomes untranslated_original. It's good this way, as it allows you to filter out what's been translated and/or edited and what hasn't by manipulating and removing search terms (very handy and time-saving for editors).
Ok, that makes sense. Translation_Available + untranslated = stuff you can edit into English. So in the future, we'll add a translation_available tag in.