Cataclysm hitting the game with all the changes to the guilds, talents, gear and stuff.
It's always like this. The friends and family beta, closed beta, less closed beta and PTR. And finally launch. The ones who get the upper hand in the next expansion are those who spend the better part of their day in reading the leaks, scrutinizing the news and blue posts and speculating on what will happen on the market.
Thinking of which, the same people who will anyhow consume the content fastest because they are running for the end game anyhow are the ones who are given the upper hand in the form of preliminary information which they can collect and put to use as plans for plunging through the content fastest.
Then again, there is always someone out there with the upper hand. Why the heck do that vocal minority have the right to spoil the fun from us who are not so keen on speeding through the levelling and willing to learn by trial the nooks and crannies of the new talents and builds? Why is it so that the whole concept of a MMO like WoW has turned into a battlefield between the players on who is faster, better and more vocal on how bad the others are?
Upper hand goes to those who devote more time to the game. Granted. But that shouldn't be taken off from the ones who do not spend as much time to the game, in the game or off the game.
The game should be equal field. Playground for all.