When Wrath came out, my leveling was guided by the highest level zone that I had access to. As soon as I got to a point where I could go from, for example, Grizzly Hills to Zul'Drak, I jumped ship and started questing there, for the better quest rewards. I liked the quests fine, but didn't feel compelled to continue the storylines, or see how the zone evolved. There was something missing there that I couldn't identify.
Cataclysm is the complete opposite. I started in Vashj'ir and couldn't get enough of the zone as I said earlier, but I wound up completing every single quest I could find (~140 of them). Hyjal was the same deal, and also in Deepholm and Uldum. The storytelling is just in a whole new zone, and while there are rough patches, I think they can definitely get smoothed out over time. However much I enjoy the PvP and Raiding game now, I'm a lore-nerd at heart and Cataclysm's questing feels like a love-note from the developers to those of us who've obsessed over the game and its story for years.
I'll be writing up reviews for the individual zones and what I liked and didn't like about them over the next couple of days.
Now that I have hit level-cap, I'm eager to get geared up before going into Heroics and farming them over the next week. I'm hoping to get into some PuG raiding this week/weekend. I'll post a list later today or tomorrow of the super-easy-to-get pre-heroics blue gear without depending on dungeon drops or a ton of Justice Points that I think should serve well enough to get us started.