Interestingly, the persistent world of the setting persists through these changes, or more accurately, it persists because of them. Not only do they provide impetus for our adventures, they also contrast what we've come to know with what is new and unknown to us. Pandaria's secrets draw us deeper into exploring what was, to us, a forgotten land, and in so doing make the world we've already known continue. Anyone who leveled before Cataclysm and then leveled a character after it can attest to the wide variety of changes to the world, and anyone exploring that world on a new pandaren or monk is benefiting from those changes. But those changes work entirely because they're changes to the world we've already come to know. We care about Pandaria because it's a new place, yes, but we also care about it because it's a mirror through which we can see ourselves, our characters, our factions. We bring the World of Warcraft we've known for years to its shores.
When we think of persistent worlds we think of being able to go back to them, of seeing them again, but not necessarily about going back and not seeing them again because the world itself has changed. But that's what the past few years in World of Warcraft has done - it's created the persistent world as a home to memories of places that are gone or changed. Going to Dire Maul now, for instance, is much the same but at the same time seeing new quest givers informs you about what's changed there. Going to Stratholme and fighting Aurius Rivendare, once an ally, and now the very enemy he helped you fight, or seeing the changes to Scarlet Monastery, Scholomance, the Deadmines and Shadowfang Keep tells you that the World of Warcraft has moved into a more naturalistic persistence, one that changes as time progresses.
Patch 5.1 features a return to the Black Temple, a chance to return to several old raids to collect new pets, and other features that highlight this forward progression, such as the Dalaran scenario. Things change, of course. But what's interesting is how those changes themselves are being made part of the experience. We go forward not only to see what's new, but to see what's become of what was once new.
Mists of Pandaria is here! The level cap has been raised to 90, many players have returned to Azeroth, and pet battles are taking the world by storm. Keep an eye out for all of the latest news, and check out our comprehensive guide to Mists of Pandaria for everything you'll ever need to know.