@Brett: It absolutely is! It's great! I'm just spending way too much time on it. I'm playing WoD instead of a bunch of other games that I've been looking forward to. But WoD is the best fun I've had in WoW since... Well, since Burning Crusade, I think. Protection Warrior (my main) feels stupidly good with the current rotation (and I'm looking forward to Gladiator Stance, DPSing with sword and board, now that's something!), Dungeons are very well designed, the Garrison is awesome and very fun to manage, professions are far less annoying than they were in the past.
The biggest upside is the questing, though. In previous expansions, it was a chore, imho. Something I did in order to get to max level while waiting for dungeon invites. This time, I'm actually not queuing for dungeons because the questing is fun! Feels more like a single player role playing game with all the cut scenes and the fact that the story telling has improved so much from previous iterations of WoW.
Oh, and there's a chance for loot you get from quests to upgrade in terms of quality - which makes completing quests all the more addictive.
Even without the raids - which are yet to be implemented - there's a lot to do. Plus, there's the 10 years anniversary. Which means you'll get to do a level 100 version of Molten Core... But the best thing about WoD:
You'll get this little bugger just for logging in during the 10th anniversary event! The Molten Corgi!