Okay, since I kind of got a non-answer in the "Questions for the Moderators" thread, I'll pose it here as a suggestion:
Currently, you have specific mods assigned to individual categories, and then the General category, which is a catch-all for which any mod will validate stories in the queue.
Since chapters in General get validated so much more quickly than elsewhere (all 29 chapters of my story Alexandra Quick and the Thorn Circle went up in the time I got about half a dozen chapters of Hogwarts Houses Divided validated), not surprisingly, people are now sticking their stories in General even when they belong in another category.
My suggestion: make all mods responsible for validating all queues. I realize that each mod probably has categories s/he prefers to mod, and categories s/he doesn't, so it's fine for them to concentrate on their preferences (and not make someone who absolutely loathes Snape/Hermione have to touch that queue ), but surely you can work out a way so that if stories in one queue are waiting significantly longer than another, the next available mod can take a look at them.