Hmm. First and foremost, I am going to have fun.
I have a rogue (blues) and holy priest (tier2). I will start off doing quests and exploring the world with my rogue. I am on a pvp server, so this may present some problems (I hate being ganked). If the ganking gets too bad, I will spend some time doing eye of the storm, and the instances.
After getting to know the lay of the land, I may send in my priest, and level mostly doing instances. This also strongly depends on who goes on what main in my small guild.
If outland is lagging badly, or instances fail to provide adequate fun, I will continue leveling my 54 shaman.
As a low priority project, I like 95% of the wow population, will make a BE pally. I do not expect her to level fast though.