I'm really looking forward to an API just cause that would allow a creation of Plex metadata agent, similar to Hama (can mix both anime shows and movies in one library, uses MAL and anidb data). I would love to have a separate Drama library in Plex, that has all the current posters and episode data etc, without waiting when it will be updated on the TVDB. I also would love to be able to sort by your ratings, just like I can sort with Hama by MAL.