The whole expansion is going to be pushed through rather quickly. We can most likely expect the next expansion late 2016. The game is already in high momentum mode and there's nothing to stop it for this expansion.
Personally I'd like to see the patch cycle stretched to at least 4 months, preferably 5 months. But that's because I want to do everything. But for those who only do crafting/gathering or only play two or three battle jobs, that is a very long time. So we end up with a faster schedule because what is at stake is the subscriptions from those who want to rush, not those who take it slow and by default will keep subscribing anyway.
The patch cycle is designed to please people who want the drive-through hoo-ha experience. Not for those who want the afternoon tea-set refill-all-you-like experience.