The world wide changes to old Azeroth with the Cataclysm event will occupy me for a very long time exploring every nook and cranny I can find of the zones I thought I knew. I leveled my priest the hard way, as holy, way before I knew anything about recruit a friend or leveling strategies. While leveling, I always got a smile at the smallest of details, things you could walk by every day out there and not see, that really helped to tie the game together.
I read every quest text and took the time to explore dungeons after my group had cleared them, just to get the full experience for what I had been looking at without seeing. Uldaman had to be one of my favorite places to go and just get lost in, there is just so much to look at and wonder at the significance it all has in relation to the lore of the game. A good example of the little details people walk by every day is the Ninja Turtles reference in the Dalaran sewers; if you don't know what I'm talking about, you've missed it a hundred times at least. Even that little jest by Blizz goes unnoticed to the majority of players.
I really can't wait to get a bird's eye view of some of my favorite places as well. I want to fly to Hyjal and see what they have done with it; it was always an interesting instance to visit, or for the more dedicated, jumping destination. The hidden troll village will be much easier to visit and I wonder if there will be any quests surrounding hard to reach areas like these.
Contest or no contest, I'll be just as happy when Cata finally gets its release.