While the go-to strategy for previous expansions has undoubtedly been to dungeon grind all the way to max level, Cataclysm changes that.
The reputation and gear we get along the way matter a lot more, not to mention some of the required content that you'd need to go back to complete at level 85 if you opted to skip it.
I think a lot more people will benefit from a mixture of questing and dungeons this time around, which I feel is more in the spirit of an MMO.