The goal of uniting the animanga communities on Wikia started back in 2007, around two years ago with the posts w:Forum:Anime Network and w:Forum:Wikia Anime (and Manga?) Project. The project has been through multiple names Wikia Anime Project; WAP, Wikia Graphical Entertainment Project; WGEP, Wikia ACG; ACG, and now Wikia Animanga, and it's evolved in ideas as I've matured as a wiki administrator. Some time ago the project was a "Are you in, or out?" type of project where wiki were either "ACG Wiki" or had no connection to the project. After a lot of maturing the project has grown, we're now simply offering what we can; The Animanga Wiki here serves as a hub to link out to all the wiki on Wika about Animanga series, as well as acting as a community hub where all the various editors around Wikia can talk with each other. As well the same shared repo service is being offered, we've got a lot of templates and a great set of css and js scripts, any wiki that doesn't want to do all that complex template work on their own can poke me and get the wiki into the sync que and get references to the shared js and css into their wiki.
I've tried a number of different ways of getting communities together. The ACG membership was the first, I've tried a general gathering of editors, and now this wiki is a central place the various communities can gather.