I kind of disagree with Mcgee. Ya haste helps you "free casting" but that's vague. Anything but EM+LvB is pretty much free casting... and considering EM LvB is easy to counter - that pretty much means it helps you with everything.

Classes moving out of LOS before your spells get off was a huge problem for shaman and still is. Haste giving you -15-20% might just make up for that. Never know. It's not going to save you from melee smash face cleave brostorm tho, which is why mine will remain retired.