Its something to think about how blizzard intends to progress WOW after cataclysm has run its course.
In the past, Azeroth has been our home in the game, from 1-60, it was the introduction to the lore and unlike outland and northrend, Azeorth wasn't set on one linear idea. You went from one area of azeroth to another, and discovered things very different and never overlapping each other, from the scourge in plaguelands, to the twilight cultists in silithus, or the elves in ashenvale or darkshore, to the trecks across the barrens. However you looked at it, azeroth was what brought us into wow, and it wasn't set on that linear pattern.
With TBC and WOTLK, well these newer places were linear, and had you travel from the start to the end, these new places, outland and northrend, were set on a path to whatever the conclusion was, the black temple, the sunwell, icecrown citadel, and all the other places to travelled though was a path that lead to the end of it all.
But, with this, there was also still azeroth, our none linear home, when the story in azeroth Wasn't based on one subject matter, such as the wotlk was the lich king, tbc was the legion or illidan/kil'jaeden. When our adventures in these new places were over, we returned home, leaving those troubles behind us and waiting for a new goal.
With cata though, its something else, the place we called home is now that linear walk, like instead of azeroth being about all different things, it is now about one thing, Deathwing, and the world destruction. Instead of going to fight whatever evil would come, this has come to us, and changed the world from its none linear story to just another one.
As the course of events have always run, to give something that can allow the story to progress, wow has, like say, had us go and fight these big evils elsewhere, and return home after, and that way it allows us to go to the next chapter.
So the real question is, how are they intending to push the story forward after cataclysm, when azeroth itself is now just like another linear front like outland and northrend. Will they reinvent all the zones after cata? Will they move us onto another planet and leave azeroth as 'deathwings' expansion?