I finished Uldum last night. Pushed through the last of the new desert zone's quests and stayed up about an hour later than I should have. Though it's billed as having less quests than Hyjal or Vashj'ir, I feel like it took longer. Particularly the tail end of the Harrison Jones fork goes slower because you end up doing one quest at a time instead of a two or three at once.
Unlike the other zones, after the initial set of quests and introduction to the main zone hub, the plot largely forks, and surprisingly enough does not come back together again. I found I really liked that, because I could bounce back and forth between storylines. If I ever got tired of one I could vacation in the other, and I did.
The two prongs of the Uldum storyline are the civil war of the Ramhaken, the new race of centaur-like cat people, and the adventures of Harrison Jones. Both are good, though the Harrison Jones branch has some (expected) groan-worthy moments.
Overall I don't think either storyline is as strong as Deepholm or Vashj'ir. Though Deathwing's reach is apparent, the fate of Uldum does not feel like it will help or harm Azeroth as much as other zones. But having choice goes a long way taking away the railroad feel, and Uldum wins points for that.
It also won a lot of points with me for its opening scenario, which involves a couple good laughs as first my character gets slighted by a camel and then witnesses a silly (but apparently effective) escape plan as set forth by Budd.
Uldum is quite possibly the most cut scene rich zone in the game, and by a long shot. Whether or not you like cut scenes may affect your opinion of the zone, but I viewed it as a positive. Amazingly enough, there is one cut scene where your character speaks! It's just a brief one word of protest, but prior to this I've seen very little said that wasn't obviously a scream of pain or some sort of scripted proclamation. It was almost a conversation... almost... in that it felt very natural.
So natural it stuck out because our characters so rarely interact in what should be dialogue.
A portion of the Harrison Jones quest chest is obviously a sendup of the Nazis in the Indiana Jones movies, but I have to wonder if there's a World War II buff on the Blizzard team since I may or may not have been reading too deeply into the quest to capture the Desert Fox and Schnottz's turkey henchman Gobbles. (The Desert Fox being the German WWII general Erwin Rommel, and the Gobbles referring to Joseph Goebbels, Hilter's minister of propogada.)
The Ramhaken storyline, while involving mobilizing a nation to go to war, and even some RTS elements, doesn't strike me as being quite as memorable. I like the Egyptian theme the Ramhaken have going for them, but their storyline isn't as powerful. Even though there is an NPC who is killed that the player could have felt connection to, his last battle and mortal wounding happens off camera, which robs the player of feeling any anger at his death. I could see less observent players not even recognizing that an NPC they met earlier in the zone is now dead by the time they finish.
By the time I finished a little over half the quests in Uldum I dinged 85. I'm terribly undergeared and won't be able to start heroics just yet, but that's okay. I intend to finish Twilight Highlands before I get serious about them, but I'll probably queue for the normal Lost City of Tol'vir and Halls of Origination tonight.
Oh, and one more thing... If you're one of those people who just really likes punting gnomes... even if you're a gnome who likes punting gnomes... there is the gnome mashing quest to end all gnome mashing quests in Uldum. Seriously.