For PvPers, you're not doing much good if you are channeling an AoE in hopes of getting an RNG proc on the knockdown instead of FF-ing a kill target / hexing / shearing / refreshing totems (specifically Tremor and Grounding).
Not to mention raiders fighting single target bosses, doesn't it seem kind of weird that we would never use our 31 point talent during an entire boss fight.
Very disappointed this is our "money-shot" Cataclysm spell.