Well, off the top of my head, the Ogame, Hawk rant, Israfel rant and World of Darkness subforums can all go. WoD can at most be taken, along with the Billy vs. Snakeman forum, and merged in 'Everything else RPG' which can be renamed 'Everything RPG'.
Movie and TV-Show Fanfiction can be merged. Much as I love it, the Super Robot Taisen forum doesn't get enough traffic, so merge with the Game Fanfiction forum and subforums.
Hawkverse might as well be axed, and FMP and FMA should probably be merged into Anime and Manga general.
Tentatively, add a Magical Girl Lyrical Nanoha board (Nanya has been recruiting from Animesuki, and quite a few regulars of the Nanoha board there are here, so the section would be used, plus Nanoha is fairly popular).
This is what I'm seeing right about now as possible changes. Of course, it's the admin's job to do this, but expressing an opinion never hurts, right?