So, I had a chance to, umm... "watch" my friend play a Death Knight all the way through the starting area. And while the play style isn't exactly my style, per se, it was fun... umm... for my friend. :) The thing that I noted most was how well carved out the quests are.
Long gone are the days of Northshire of kill lesser npc, kill npc, and then finally kill greater npc. The quests produce an excellent story that's told, not only through the quest text, but also through the actions you're required to do. I've mentioned before how much I enjoy the Dranei and Blood Elf starting areas. And these are along the same high quality... even better in my opinion. So I may play multiple Death Knights just so I can enjoy these great quests.
My only complaint would be that there wasn't a "Go find your trainer" quest. I knew that I should go train at 56 or so, but... umm... my friend didn't know where the trainer was. Good thing for the tracking function, but even then, it wasn't like the trainer was really near anything that I had been to before. The faster running you get in Ebon Hold as a quest reward helped a lot though.
I also noticed the efficiency of quests. I'm a big fan of leveling guides simply because it helps me maximize my xp/hour. I may have to get quests in 3 areas so that I can complete them all in the one place. But if there were multiple quests in one spot, their objective was usually in the same place as well. If the trend continues in Nothrend, we can all be effective... even without using TourGuide.