Howdy!
Aight, here is just some food for thought about WoW's leveling system. In WotLK, Blizz implemented heirlooms in order to speed up the leveling process for alts. In Cata, they devoted a ton of resources to redo the leveling experience from 1 - 60 which includes making questing & instances more compact/streamlined. In Cata (maybe WotLK) and definately MoP, Blizz reduced the amount of experience needed to level up overall. Now in WoD, Blizz plans to give all players who buy the expansion (Returning, new, and continuing) one free character boost to level 90. Basically recent expansions have made the leveling process as a whole a giant speed run. This, of course, shortens the longevity of the game. However, in order to keep players playing, Blizz only slightly increases the levels each expansion and implements, over time, gear of increasing power which artifically levels players.
Now if you think back to vanilla WoW, one level hardly made a difference in power due to complex talent trees, broken classes, and whathaveyou. So even level 60 raiders and twinks would occasionally get roflstomped.
Now if you think about MoP, the power gap between fresh 90's and an SoO geared 90 is vast due to sheer numbers (class balance be damned). It would seem that in order for players to level and gear up, Blizzard has foregone the old method of actually gaining levels in lieu of gaining item levels.
From what I can see:
Pros: Everyone is at max level which means the only thing people need in order to be competitive is gear. Everyone can play with their "friends."
Cons: By speeding up the actual leveling process, the hours put into leveling content (Virtually everything from lvl 1 - 89 and thus the vast majority of the game itself) is sped through in order go through the artifical leveling process of getting gear. This makes the majority of the time players spend in the game on the same content over and over again for months instead of all the other actual content. The leveling process, which was a guaranteed thing with experience points, is now random, due to rng gear drops. BiS raiders can go on an unstoppable rampage whenever (Ex. My friend Daethite used Censer of Eternal Agony on Timless Isle. People formed a raid on him and he still killed them all for hours.).
Same: The level grind is replaced with a gear grind from Raids or a rep grind to get gear.
What do you guys think are the pros, cons, or what is the same?