I've been away for years and when i came back to WoW i found The Burning Crusade being replaced with Wrath of The Lych King. And within months the world of Azeroth had changed in a cataclysmic event.
I found levelling new character laughable easy and fast. Also there were more in-game jokes then I remembered from the Vanilla and TBC time I levelled my characters.
You will find a reference to CSI, when you go quest in Westfall. One of the first quests you run into you will fin Horation Laine investigating a murder. He pops up as well in the renewed Deadmines.