cata had huge potential,
who among the veteran warcraft fans from the days on WC1 didnt want to visit the elemental plane?
add to that the war of the ancient raid and a major xpac villian so powerfull and big that normal methods of killing final bosses which we used up untill now wouldnt be enough anymore to kill him and so a time travel is needed...
alas, in the end the 1-60 revamp took so much time they had to start the xpac already behind schedule so alot of what was planned got cancled or narrowed down and blizz had to fill in the gaps with easy reused designs of instances and raids allready exist in the game.
the end result was a lacking xpac but the idea and lore behind it is way better then what i am seeing in MoP which is killing the same old panda lore bosses which the panderans killed ages ago without any outside help ,
and while we are not doing that , we tend to thier farms while they sit and drink beer all day..