NATURE'S GRACE: Now procs from non-periodic spell criticals (old: all spell criticals).
So direct-damage spells (e.g. Wrath, Starfire, Moonfire's initial hit) or direct-healing spells (e.g. Regrowth's initial heal, Nourish) will be the only ones that can trigger the 20% haste effect from 3/3 Nature's Grace. This is definitely a nerf for Balance concerning Starfall and Hurricane crits, but it's also a nerf concerning specific gear sets. Moonfire's DoT component can crit if you're using Balance 2-piece Tier 9, and a Restoration druid rocking 4-piece Tier 9 gains the ability for Rejuvenation to crit.
For Balance's AoE situations and Starfall cooldowns, it's an out-and-out nerf, albeit a limited one given Starfall's cooldown and the unlikelihood of Hurricane playing a major role in any given boss fight. Otherwise, it's also a nerf directed at Tier 9 bonuses, unless Blizzard's planning on future tier bonuses (or class changes) that will make periodic damage and/or healing crits a routine thing. Stay tuned.