One of the changes between The wow powerleveling Burning Crusade and Wrath of the Lich King that I'm noticing most strongly now that I've cleared most of the solo and small group quests in Northrend (I needed money for crafting) is how accessible major lore moments are, and how much lore is now being created in the massively multiplayer game, rather than simply being resurrected for it. Yes, we're seeing the machinations of the Lich King, that fusion of Arthas and Ner'zhul we saw created at the end of Warcraft III, but we're also seeing in the Storm Peaks and Sholozar a great deal of new information about the Titans, who they were and what they were up to on Azeroth, and their contrasting opposites the Old Gods. The Yogg-Saron storyline has fingers in Dragonblight, Grizzly Hills, Storm Peaks, and Icecrown at the very least and the quests that reveal the conflict not merely between this vast, formless entity and the Titans but even against the Lich King's forces in Icecrown are surprisingly deep and complex for ones you can do solo or in a group of three or four people.

There were a lot of lore quests in TBC, of course, but often the coolest ones required at least five people to get through if not a full 25 man raid group. So far in WotLK I have run all of the big new lore quests either solo or with a small group of two or three other players. The Admiral Revealed in particular was a great big lore bomb for the size of the group that accomplished it. There are huge revelations available in game that change the very foundation of the Warcraft setting and they're very easily accessible.