Let me make this clear: I have nothing against night elves. Well okay, I do, but that's not the point. The true problem is that they have the lamest, most boring, most emo, most awful starting zone ever. Teldrassil is a worthless pile of crap.
The new quests aren't majorly different in theme, but the way they are given is a lot more fun. Where to start?
I like the 'mini-elite' named quest mobs. It's cool to see the portrait of them with the quest. It fixes that weird problem of "How did I know who to kill when you never told me and let's face it, I'm pretty sure most enemies don't have their names floating over their heads?" The little bit of added background on them is a nice touch. The quest 'bosses' themselves feel a bit tougher. Not hard, but just they take a few more hits. It's not adding challenge, but it is helping to differentiate them from all the trash around them.
The mist in the cave. Players who have done it will understand. Players who have not done it, I don't want to spoil it, so just imagine a mechanic that doesn't ruin immersion but can help prevent getting lost in caves.
Earlier, the teleport out of Fel Rock, a nice touch. It shows some recognition that some people get lost in caves and do not much enjoy having to battle in, battle to the right path, then fight the same trash all the way back out, hopefully without getting lost this time. Respawns are easily deadly in caves.
It helped that I somehow found two rare spawns. They dropped greens. I was floored.
Dolanaar is slightly too spread out, such that I ended up not seeing a quest indicator and lost the last quest path. However in Blizzard's defense, they had established a trend of "talk to the moonwell guy, then go to a moonwell", so I should have known to check for quests at him again.
The profession trainer in the newbie area is a great idea. Finally, we get start professions on time, without going way out of our way. That means they fit better into leveling. The descriptions of gathering and crafting professions was well-done. Going even further to describe the individual professions and the pairings, just great. Something is possibly lost in new players not figuring this out themselves, but something is gained in them not ending up poor and ignorant, stuck tabbing out for professions guides to fix their major mistakes.
What confused me was that there didn't seem to be much chatter about night elf mages. I'd have expected the starting NPCs to talk more of the Highborn and Shendrelar.
So far I'm very please with the Sundering.
Oh wait, no, I forgot: It gave me the achievement for surveying the damage when my paladin hadn't even left Dalaran yet. That irritated me. I'm assuming it's tied to some sort of zone discovery and since I had them all, there you go. On a related note, my hearthstone had been Light's Hope Chapel. They reset it to Stormwind. The shiny new AH looks weird.