Right now there's only a few pages, but already there's lots of theorycraft, guides to hunter loot and quests, and even a round of hunter-oriented comics (well, some of those are better than others, but it's still a work in progress). They don't have nearly as much pet info as Petopia yet, but being a wiki gives them lots of room to improve.
In fact, the wiki format lends itself very well to WoW info, just because this is a social game consisting of a lot of shared knowledge-- WoWWiki has been proving that theory for a while (and they've got lots of hunter info there as well, along with plenty of other necessary information). But it's definitely awesome to see a wiki dedicated to the ins and out of a particular class, and hopefully what Eldariel has built will bring lots more editors and contributors so more hunters can share what they know with at least a little privacy from the prying eyes of others. In fact, where's my Shaman wiki?