I think blizzard have just a minimal team on wow now to keep it ticking over
they know the product is end of life nothing lasts for ever
their A team is now on Diablo and titan
competition is getting stronger rift had a good pop but was too similar swtor will take a bigger swing at them and will retain some of their players I think
they desperately need new engine new game new experience people expectations are now higher and more demanding
the problem is the world is changing fast and blizzard are not keeping up they need to innervate (ironically now its been nerfed lol) not flog a dead horse.
a nice frostbite engine with dynamic first and third person game play no quest or instances but living a real story effecting it's outcome creating a more player driven choice like environment they need to respond to the market.
I think what ever they do to wow now even a whole new planet to explore it will just be more of the same (unless the planet is a forest moon called endor and the mobs drop glowing light energy swords and have small bostaff wielding teddies..... hang on a cotton picken minute ewok = pandaren arrrrhhhhh

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