It has been a while since I posted anything about my progress on my latest Main...I ma not at level 57, less than 2 bars from 58. I have started questing in Western Plaguelands.
Unlike many of my friends who play World of Warcraft, I do not go to the Outlands until I am level 60. Yes, I know you can go there at 58, but I feel it is a great disadvantage to do so.
First, you can use up the easy quests that would otherwise get you to level 70, leaving you no option but to grind your way on the last level or two. Second, the initial quests go a low slower because you are comparatively underpowered. I prefer to be as strong as possible when I do my quests, and I suspect I can more than make up the extra time spent in Azeroth by burning through the Outlands quests faster.
In fact, I plan on doing all the quests outlined in the Horde leveling guide that I use, even if it takes me to 61 before going to the Outlands!