One of the main problems our readers cited was leveling boredom. The game before Outland is a bottleneck for casual players who want to explore other classes and playstyles but find that getting where they want to be with their new favorite alt would take more tedium and repetition than they're willing to tolerate. Some have the patience and dedication for it, but for others it feels like an impassible jungle.
Stranglethorn Vale, sometimes called the "Stranglethorn Hole" (coined by Tobold in reference to black holes, I think), has been the prime example of 1-60 leveling boredom, because at some point between levels 30 and 45, quests in most other areas just dry up, and you're left with little choice other than to help out the goblins in Booty Bay. The Gaming Fascist complains that he couldn't get any characters through the Vale without it feeling like "an affliction or a chore, something I don't really enjoy and fall back to when times get too boring." This was especially infuriating for him since he apparently chose a PvP server and he got ganked a lot there. Anyone tends to feel frustrated and hopeless when your goal is so far away that you have no reasonable means to achieve it.
We took a light-hearted look into the future a couple weeks ago, to see what solutions might present themselves in a few years as this problem gets increasingly severe. The fact is that has to be done for casuals who can't or don't want to go raiding, and if trying out new classes and isn't really a feasible option, then what's to prevent them from feeling stuck with nothing to do? More reputations to grind?