Having spells interrupted by auto-attacks is just plain ridiculous. You can't defend this. No caster in their right mind would agree this is how PvP should be played. Surecast and equanimity should not be affected by CC's either, but the real problem is melee players being able to interrupt casters with zero effort. Name one thing a caster can do to a melee player with zero effort.

Obviously spells will have to be re-balanced in PvP after this change, but it is for the better.