What makes this tricky is the use of filters. It would be real easy to get the "Save status" functionality work with ajax, but then an ajax script would have to refresh the list as well.
I'd like that for One Piece as well.
Actually that could be used for any anime series, especially since the english airing and seasons doesn't always follow the japanese one...
Right now if I click on a series' own page, there's no highlight distinction between future and past episodes, like on the 'myepisodes' page. There could be a checkbox to use that colouring on the ind ...