I don't normally do two posts in one day but I just read over at another blog something interesting about Nature's Grace.
With talents, Wrath becomes a 1.5 second cast. When Nature's Grace procs off of a crit it reduces the cast time of our next spell by .5 seconds. Since the GCD is 1.5, this proc is wasted when used by another Wrath spell during spams since you still can't cast Wrath more than once every 1.5 seconds.
Maybe making a stop-cast macro to cast Starfire when it procs might not be a bad idea?