Mudsprocket is the main quest hub for both Alliance and Horde, though most quests appear to be Alliance based. Other new quest hubs include Tabetha's Farm and additional quests on and around Theramore Isle. One of the new quests centers around the disappearance of the King of Stormwind and involves both Jaina Proudmoore and Bolvar Fordragon
Other changes include the arrival of the Grimtotem Furbolgs, the dragonkin outside Onyxia's lair losing their elite status and the introduction of a new sea beast.
Szilia doesn't give out any loot rewards, but with new Epics introduced in the lower levels, maybe the quest rewards will be better than usual. And Alliance really needed an alternative to the 15 level grind that is Stranglethorn Vale.