Not sure if this has crossed anybody's mind, however I have a feel in my gut that Blizzard is working on changing the very core of the game with this expansion, meaning that patches will be actually bigger and offer more.
A simple and rushed out example would be introducing a class in 9.1 patch. Since the game is moving towards more dynamic style, they perhaps will focus on larger content updates and/or adding more meaningful stuff via patch cycle.
No big initial features to showcase kind of made me think about it the way I do. And before anyone bashes my skull in, I'd love to clarify that I am open for all sorts of discussion and would love to see what people think about it, whether it is optimistic or pessimistic, feel free to share it - though I'd appreciate elaboration and being constructive.