Luckily, it looks like we may not quite be done yet. Peacekeeper Jadaar has been standing in the World's End Tavern arguing with Investigator Asric for quite some time now, but if you talk to him, he still acts like he's standing outside Griftah's tent. World Event Designer Kisirani answered someone's question on this by saying it's been on her list and she's getting to it. Certainly, this could mean she just plans to update his speech to explain that the investigation failed and Griftah is back, but then again, it could mean we'll see more of this epic storyline. He may not have ended up being the real Zul'jin, but maybe he's still got a few more tricks up his sleeve. I'm thinking that at the least he'll start selling "genuine artifacts from the first Northrend expeditions" soon. Maybe "Defeat of Illidan Commemorative Coins."
It's definitely a storyline I'd love to see evolve some more. Even if he's not exactly M'uru, Griftah's earned enough of a place in Warcraft lore that he can't just sit comfortably in Lower City pushing trinkets.