Only about 25% of it, really, considering the 1-30 content goes by faster than the stuff afterwards.
And I do agree that leveling is fun and part of the game... but by the time the expansion hits, I'll have already pretty much memorized all the 1-30 content available backwards, forwards, sideways, slantways and crossways. There won't be side quests to do, since I already did them all leveling my other classes. It'll just be the grind. I don't mind skipping that part, and it saves the devs from having to come up with new low level areas to keep things fresh in.
