This article has gotten some flak on the WotC forums because it doesn't present any caster-form options, but in my opinion that isn't necessarily a bad thing. There will be more Druid material in Dragon in the future, and I definitely hope that we get some new caster-form goodies. This article, however, had a definite theme of customizing your beast form so that different forms granted distinct mechanical advantages. This was an issue with Wild Shape when it was first presented before the release of the PHB2. People complained that while it gave the Druid access to a different suite of powers, the player's choice of specific form was just cosmetic. Even from the start some attempt was made at differentiation; after all, the PHB2 had Enraged Boar Form and Ferocious Tiger Form as Heroic Tier feats, Hunting Wolf Form and Stalking Panther Form as Paragon Tier feats, and several Daily slot items in the vein of Primal Wolf, Primal Wolverine, etc.
This article published several more Primal X powers, as well as some utilities and feats that support beast form specializations. I'll review each new feature, since the article was fairly short.
Heroic Tier Feats
Each of these feats augments one of the Druids original 3 beast form at-will attacks.
Patient Hunter: This is what Pounce should have been from the start. At least now it compares more favorably to Swarming Locusts. Druids with feats/equipment that enhance their damage when they have CA might consider this power now, especially if there's a Rogue in the party.
Ruthless Killer: Swarm Druids just became even better defenders. This feat would actually make real defenders jealous! What's better than a mark? At-will immobilize (albeit with the caveat of staying adjacent)! This might be a candidate for slightly overpowered, but not game-breakingly so. Essentially, a defender's mark is a form of soft control (do this or get an attack debuff and some sort of punishment), whereas Ruthless Killer gives a Swarm Druid hard control (the enemy has no choice in the matter). They still can't punish enemies for attacking nearby allies, but they sure are sticky now.
Unstoppable Beast: Useful for any off-tanks that want some extra positioning. Even Predator's might find it useful, though. Push someone into a zone/hazardous terrain and then guard the edge. If you can slide 2, this is useful for staying 1 square away when using Primal Wolf (for charge protection) while still benefiting from the increased slide range.
Paragon Tier Feats
Most of these serve to emphasize specific tactical strategies.
Brutal Grappler Form: Hey, this synergizes quite nicely with Latch On, Constricting Coils, and Scavenger's Prize! If you've enhanced your damage when you have CA you can be a pretty darn good isolating striker, especially if you have the Defensive Advantage feat (better AC when you have CA). In terms of actual grab attempts, it still doesn't make up for the fact that Str is a dump stat for you. Only bother with this if you have grabbing powers. Any build can be a grabber, but Predators should focus on grabbing opponents that are unlikely to use Str/Athletics to break the grab since they have a low Fortitude. Predators also have some notably good riders on encounter grab powers (Latch On and Scavenger's Prize). Swarm and Guardian Druids, conversely, shouldn't grab foes that are likely to escape via Dex/Acrobatics checks since their achilles heel is their Reflex. For any grabber, artillery and other ranged enemies are prime targets (even if they break the grab right away, they've still wasted a move action to do so and will thus provoke OAs if they attack).
Fierce Thrasher Form: I already have Rushing Cleats. I'm definitely taking this too. Anyone who likes forced movement will probably do the same. With both, you get a slide 3 with Savage Rend. Basically, I use Savage Rend as my primary damaging power since I can set up situations where I'm charging into CA fairly frequently (and have damage boosts for charges and CA). Now I can also throw my enemies all over the place while doing so.
Scuttling Crawler Form: Hey, my cat form doesn't suck at climbing trees anymore! It's about time they released this feat. This was a major point of contention with wild shape when the Druid preview was first released, namely because Str is a dump stat for most Druids and yet, paradoxically, a lot of actions that animals should be good at require Athletics checks. Personally, I would have preferred a feat that lets you use Wis in place of Str for Athletics in beast form, but that may have been overpowered.
Venomous Fang Form: Given that Druids don't have a plethora of poison powers, you're unlikely to have very many of them unless you specialize in poison attacks. Furthermore, you can MC Assassin and get better poison resist/immune penetration. Pass.
A mix of Daily attack powers, all of which are Primal Form, and Daily utility powers, which grant the Druid abilities which Wild Shape does not normally confer, much like Skittering Sneak and Black Harbinger from the PHB2.
Primal Spider: Solid and flavorful. Surprisingly inferior the the similarly themed Wizard's Web though.
Treetop Lurker: A Daily form utility, and a pretty specific one at that. Some Druids will probably take it for flavor reasons, but I can't really justify picking it for most builds. Maybe if it was 2nd level.
Primal Serpent: Assuming that this power doesn't contain a typo and you really can't save from the poison damage, it's still pretty weak. This level has some steep competition, including Primal Wolf, Summon Crocodile, Entangle, and Sunbeam. I really can't justify taking this, and my Druid's a Coiled Serpent (thought to be fair I don't use snake forms exclusively, or even most of the time).
Diving Fin: Wow, lame name. But still, a much sought after concept. I honestly expected this to be in the PHB2, and was a little disappointed when it wasn't. Then I forgot about it by the time Primal Power was released, but I'm glad the concept was finally published.
Primal Boar: This is actually pretty decent for striker and controller purposes. Position yourself so that you provoke OAs from anyone that you want to knock prone, and unless your DM is metagaming even intelligent enemies should take the bait the first time. It's slightly annoying for Predators that the powers in this article tend to be Con based, but at least the bonus isn't that critical for the function of the power.
Primal Crocodile: The -2 penalty to escape grabs probably won't be enough for most grapplers, especially if the enemy targets your weak NAD (tee-hee-hee). Still, if you're not a Predator this isn't overshadowed by Latch On quite as much. Plus it synergizes with Brutal Grappler Form.
Primal Lion: I actually really like this power. It's a solid mix of controller, leader, and striker, it evokes truly spectacular imagery (ok, that one's subjective), and it targets Will! An excellent pick for this level. Did I mention it also only targets enemies? THP is Con dependent but this would still be worth it for Predators.
Primal Panther: This one I'm not so sure about. It's pretty much a pure striker power, but if you have Pounce you can basically give yourself permanent invisibility for the entire encounter (against a particular foe, that is). Anyone who wants to be a Displacer Beast will love it.
References: article link