Here's two more previews from Zul'Aman floating around the Interwebs. Games Radar has a nice little preview up, including info on the bear mount (!), which (apparently-- it's not confirmed yet, although come on) drops from Narolakk, a bear boss that you actually have to chase across the city. GR says the instance will be "a spiritual successor to Zul'Gurub" (music to the ears of many players, including me), and that it'll be a little brighter and more wide open than the other late game instances, which should get yet another mark of approval from players.
Frictionless Insight also has a preview, in which they say the four animal bosses will consist of Bear, Eagle, Lynx, and Dragon Hawk spirits. Strangely enough, we've already heard that there will also be a "god of evil" as well as a witch doctor and the end boss Zul'jin, which means there may be more than the six bosses that Blizzard first hinted at. Additionally, we've heard from quite a few sources now that the Zul'Aman trash will be very sociable (as in, there will be mobs that bring more if you're not careful), but Frictionless Insight says the dungeon itself will start with a boss, not trash, so even more good news for most raiders.
All in all, Zul'Aman seems to be shaping up nicely. There's no telling when we'll see it on the PTRs, but I would be very surprised if Blizzard didn't let us play it (or at least see a preview of it) at Blizzcon. Storm the castle!