- Nature's Grasp: Now has 3 charges, up from 1.
- Typhoon mana cost has been reduced from 32% of base mana to 25% of base mana.
- Starfall damage has been increased. Now causes 563 to 653 Arcane damage (Up from 433 to 503) and 101 Arcane damage (Up from 78) to all other enemies within 5 yards.
From my PvE perspective, the Nature's Grasp change will pretty much only be helpful in fights like the Faction Champions in ToC. I believe that, other than that, it will still be better to simply run in to the tanks if you end up pulling a mob.
The Typhoon change makes it slightly more efficient to cast Typhoon. However, unless you've glyphed it, you are still likely to use it only in boss fights (or to knock adds you pulled back to the tanks). I am trying to think of trash groups in ICC where you may wish to use it every time it is off cooldown. I suppose you could at any point where the trash is largely up against a wall. The important thing is to avoid pushing them too far from the tank or, worst of all, into another trash pack. Frankly, I still won't use Typhoon on boss fights except when running. I don't think it's worth the GCD (though someone should let me know if the theorycrafting indicates otherwise).
The Starfall change is quite welcome. It seemed like a lackluster top tier talent to say the least, especially since it has such a high risk of pulling additional mobs in any non-boss situation. It's a low damage AoE on a long cooldown. Hopefully this will fix at least one of those issues. We should already have been hitting it every 90 seconds though, so I don't think this will have a major impact on PvE rotations (or, in all likelihood, dps). I suppose that, in high movement fights, it may now be worth dropping Glyphs of Starfire and Insect Swarm to take up Starfall and Focus. The damage increase would need to be pretty big though, so we'll have to wait and see.
EDIT: The Starfall changes take it from 433-503 damage per star (20 stars total) to 563-653 damage per star. Assuming you hit it every cooldown and have 3000 spellpower, this will increase dps from this spell from 137 to 206 (unglyphed with a 90 second cooldown) or from 168 to 252 (glyphed with a 60 second cooldown). In other words, the glyph used to get us an additional 69 dps, and is now worth 84, by my back-of-the-napkin math.
The question is, is it worth dropping the Insect Swarm glyph for the Starfall glyph now? Insect Swarm scales better with spellpower than Starfall does (120% to 100% per duration), and the 30% increase to damage from the glyph is applied after spellpower has been factored in, if I understand it correctly. Based on 3000 spellpower, the Glyph of Insect Swarm is therefore worth 122 dps, if I've done the math correctly (407 dps to 529 dps).
In damage terms, the Starfall boost is decent, but still not worth dropping the Insect Swarm glyph for. However, it may be worth switching in order to provide the 3% hit loss in some ICC fights, if you are the only boomkin. Regretfully, this will cost you around 38 dps if I've done my numbers correctly. Note that this is pretty minimal...you are doing 11,400 less damage over the course of 5 minutes, or thereabouts. On a 10-man, that's less than one-half second of raidwide dps. It is worth it to give the buff to tank survivability.
Thus, if you are the only boomkin in your raid, use the Glyph of Starfall, not Insect Swarm. Otherwise, stick with Insect Swarm. You'll do more damage.