For all the people here arguing, I recommend you logging on the PTR, and testing it out. I sent out several bug reports with some of the tricks that were only possible with spell batching, and they fixed almost all of them.
From what I can tell, blizzard is opting for a hybrid approach, where most things in game are on a 10ms batch, while some interactions are still on a 400ms batch (or at the very least it simulates the same effect).
From that I can see, the developers are committed to preserve all those quirks while improving the game responsiveness. If you log on the PTR and feel like something in the game is missing REPORT IT. Try to be as much descriptive as you can to make sure the developers can address the issue.