The worse thing about Mount Hyjal is the ugly shade of WOW-green that Blizzard love so much, but otherwise I thought the slow push forward through the zone, the goal of freeing the ancients and slowly taking back the land was enough to keep the forward momentum up. There were a lot of 'kill X' or 'gather Y' quests, but they were short and uncomplicated, and usually had some sort of twist to them that either made them funny or otherwise entertaining. I guess I've just really appreciated the more directed progression through the zone, it makes it feel like less like an MMO trying to support a single-player story within itself and more like a single-player experience with a fully equipped MMO architecture. I mean, it's all a magic trick, because it still very much an MMO with all the limitations an that come with it, but I thought it did a really good job of mixing the two together in a pretty organic, fun way.
I just finished the twilight encampment stuff, which was probably the best disguise quest-chain I've played it the game. The finale looks like it's going to be cool.
The jousting sucked for me because I play with a relatively high ping, and it just wasn't responsive enough.