How should I gear?
Feral druids use leather with agility as the primary stat.
Weapon DPS - Directly scales white damage, Ravage, Mangle and Shred. All of our attacks are normalized, so weapon speed is irrelevant. Weapon Top End damage is irrelevant. The higher the Weapon DPS, the better, and it is a considerable DPS gain when increased.
Agility - Our best DPS stat that we have direct control over. It's also the stat you'll find most on gear, and the stat you'll want to gem and enchant for in most cases.
Strength - Grants flat attack power. Due to multipliers, Agility will always be better. Since it does not appear on leather gear and we can gem for either strength or agility (and agility has a edge, plus can be used for tanking as well), the only place you might find it is on accessories such as rings, and on a few weapons. It's not a stat to seek out, and should be avoided if at all possible.
Hit rating - Hit rating gets passed by almost all other stats at most gear levels according to calculators. It should not be gemmed for, although it is still useful to have a reasonable amount on gear to smooth your cycles. The exception is if you are crit-capping, when it becomes very valuable.
Expertise rating - Expertise has exactly the same effect (reducing the number of attacks that fail to land, only by reducing dodges rather than misses) as hit, and the same conversion, and so it has exactly the same DPS value up to the dodge cap. If you're the sort that obsessively hit caps, don't forget to expertise cap too.
Mastery rating - Increases the damage of our bleeds. Usually is our strongest secondary stat.
Crit rating - crit rating provides a little more crit per point than agility, but no AP. It comes in at a fairly similar DPS value to hit, expertise, and haste.
Haste rating - Increases white damage and energy regeneration (both directly and through increased Omen of Clarity procs). It also increases the number of procs from PPM based weapon enchants such as Berserking and Mongoose. A solid stat. Attack speed is calculated as 1 / (1 + haste%/100). e.g. with 9% haste, your attack speed is 1 / 1.09 = 0.917. Yes, ferals can attack more than once per second.
Attack Power - A stat that does not appear on gear anymore for the most part. If there is no other choice, it can picked up, but Agility will be better DPS.
1 Strength = 2 AP (3.17625 AP with talents and full raid buffs)
1 Agilty = 2 AP + 0.00307831% crit (3.335063 AP + 0.003393836% crit with talents and full raid buffs)
1% Hit = 120.109 Hit Rating. The cap starts at 961.
1% Dodge = 4 Expertise = 120.1088 Expertise Rating. The cap starts at 781.
1% Crit = 324.8536 Agility = 179.2801 Crit Rating. White cap is 80.8% character sheet.
1% Haste = 128.0572 Haste Rating
1 Mastery = 179.2801 Mastery Rating = 3.1% increased bleed damage.
Meta: Relentless Earthseige Diamond (+21 Agility/3% critical damage), Chaotic Shadowspirit Diamond (+54 Crit Rating/3% critical damage) (Cataclysm equivalent of Relentless Earthseige Diamond currently unknown.)
Red: Delicate (Agility)
Yellow: Adept (Agility/Mastery), Deadly (Agility/Crit), Deft (Agility/Haste)
Blue: Glinting (Agility/Hit Rating), Shifting (Agility/Stamina)
Unless a piece of gear has a particularly good socket bonus, it's best to primarily socket pure Delicate gems. A 14 agility socket bonus will usually break even, it's worth using Orange gems to get a socket bonus at or past that point. In general it is not neccecary to gem for Hit or Expertise. Preliminary math indicates that the WotlK Relentless Earthseige Diamond is better for DPS than the Chaotic Shadowspirit Diamond. A Cataclysm equivalent that provides Agility along with the crit damage increase however would be superior.
Also keep in mind that all of the Crit multiplier increasing metas currently have "requires more Blue Gems than Red Gems" as a requirement. Unless your gear has a lot of blue sockets with Really Good socket bonuses, gemming to meet it will result in a net DPS loss (However the secondary effect can be good enough to offset the stat loss). For certain gearing configurations using Fleet Shadowspirit Diamond (+54 Mastery Rating/Minor Run Speed Increase) or Destructive Shadowspirit Diamond (+54 Crit Rating/1% Spell Reflect) may be better. (Yes, it is retarded. At this point I've mostly given up in disgust at trying to provide feedback to the developers, someone else is welcome to try.)
Helm: Arcanum of the Ramkahen (+60 Agility/35 Haste Rating)
Shoulders: Greater Inscription of Shattered Crystal (+50 Agility/25 Mastery Rating)
Cloak: Greater (+65) Critical Strike or Major (+22) Agility
Chest: Mighty (+15) or Peerless (+20) Stats
Bracers: Greater Speed (+65 Haste Rating) or Greater (+65) Critical Strike or Draconic Embossment - (+130) Agility (Leatherworker only)
Gloves: Mighty (+50) Strength or Greater (+65) Mastery
Legs: Dragonscale (190 AP/55 Crit Rating) Leg Armor
Boots: Major (+35) Agility
Rings: Agility (+40, Enchanter only)
Weapon: Landslide (Proc: +1000 AP for 12s) or Hurricane (Proc: 450 Haste Rating for 12s) or Mighty (+130) Agility
New to Cataclysm this allows you to convert 40% of a secondary stat on given peice of gear to another secondary stat. Reforgable stats are Critical Strike Rating, Dodge Rating, Expertise Rating, Haste Rating, Hit Rating, Mastery Rating, Parry Rating, and Spirit. It is not possible to reforge to a stat that is already on a given peice of gear. For example, if it has Hit and Crit, you cannot reforge the Hit to more Crit.
There is nothing special about min/maxing this. Simply reforge your weakest secondary stat to your strongest while keeping in mind Hit and Expertise caps.