Since we have a few players who are playing as mains or alts feral dps, I thought I would post my rotation and explain my spec mechanism.
The aim of this spec is to maximise the damage output from shred ability, and at the same time, reduce the costs from it.

Firstily i will explain a bit about the talents that need to be chosen.
There are several talents that are at work here. One of them is rend and tear, which increases the damage done by shred by 20%. Mangle is a crucial debuff, especially if you don't have an arms warrior who can do the trauma debuff which increases all bleed damage by 30%. It's also worth mentioning that, as stated in Shred ability note, effects that increase bleed damage also increase shred damage, which in our case, those abilities are trauma and mangle. These are the 2 reasons for which mangle or trauma are so important: bleed damage which are vital for cat druids and shred damage, which makes the entire DPS for Feral DPS.
Another issue when playing cat is energy management, that's why Shredding attacks is among the most important talents, as well as all talents that increase critical strike chance and damage have to be taken. Here is a link to my talent build http://eu.wowarmory.com/talent-calc.xml ... 0000000000 .

The abilities that i use are as follows: mangle for the 30% bleed damage debuff, savage roar for the 30% physical damage increase, rake and rip as bleed effects (rake's damage isn't very important but since I am using the Tier 8 set bonus, i get twice as many clearcasts from Tier 8 instead of one, which would be from rip), and ferocious bite for the high burst damage but it can sometimes be tricky to use. Talking about glyphs, I will now also mention the glyphs I use. Those are Glyph of Rip, Glyph of Savage Roar and Glyph of Shred.

So my rotation goes as follows:
- Faerie Fire (Feral)
- Berserk
- Mangle
- Rake
- Savage Roar (with 2-4 combo points up, this depends on how often I crit, which is influenced by one of the talents, meaning that if you crit, you gain 1 extra combo point)
- Shred up to 5 combo points
- Rip
- Shred up to 5 combo points
- Renew Savage Roar
- Continue Shredding and replacing Mangle or Rake as needed, as they are very important debuffs
- When low on energy use Tiger's Fury (remember to have 3/3 King of the Jungle)
- When you have 5 combo points, Clearcast and Savage Roar or Rip will not vanish anytime soon, you can use Ferocious Bite for the extra burst damage (this can be especially useful in very short fight such as Hodir Hard Mode or Sartharion 3 Drakes up, zerg strategy).

The rotation I use is slightly different than the one(s) they suggest on elitist jerks. Based on some research I've done on abilities and some advice from other people who were playing as cat dps-ers themselves, I developed my own rotation using all these abilities. The reason for me using only 2-4 combo points at the start of the fight is to get all needed debuffs for shred in shorter time, as Savage Roar is affected by combo points only in terms of duration and not percentage of extra damage gained. Also, I tend to use Berserk at start most of the time, except for XT-002 in Ulduar, where I keep it for the heart phases. The reason is the same as in the case of savage roar, to provide a high damage output at the start of the fight and then I just have to fight to maintain the high amount of DPS.

To sum up, the above mentioned debuffs need to be maintained up, Shred is the main attack when using this rotation and Ferocious Bite whenever possible. This is why i suggested using Rake along with Rip, getting as many clearcasts as possible. This reduces energy consumption as this is one of the biggest problems as Feral DPS and if you are lucky you can get Clearcast after Clearcast and easily top the damage meters and make the tank hate you (use cower if you are in danger of overaggroing but since cat is generally a low threat generator, it is largely tank's fault if you overaggro as feral DPS).

The advantage of this rotation is that it provides a very high amount of dps, probably the highest possible with cat, but it comes at the cost of flexibility. It is always required for you to stand at the back of the mob or boss, which can be tricky sometimes and it also requires a dedicated spec, while some players prefer playing cat and bear using same spec.

As for the stats required, obviously you need to be hit capped (263 hit rating or 8%) as well as expertise capped (26 expertise or 6.50%). As for enchants, attack power shoulder and head enchants should be used (PVE or PVP ones if reputations are not high enough for the PVE ones), bracers should be enchanted with 50 attack power or the Leatherworking one if you are a Leatherworker. As for the weapon enchant, I currently have +110 attack power, but Mongoose is also a very good and viable option, and it has the advantage that, along with +110 attack power one it can be used as a tanking enchant if you are also tanking with that weapon. But, if you are sure that weapon is not going to be part of your tanking gear, Berserking might also be a very good option. These enchants, of course, depend on personal preferences. Rest should be enchanted with agility all way round, because agility is also applied to attack power or if needed, hit rating enchants (i am using 12 critical strike rating and 12 hit rating on boots myself, to maintain stat balance). The formula for calculating attack power in cat form is like this: normal form attack power + agility + feral attack power provided by weapon + a given number stated in the cat form note (should be 124, don't remember for sure).

And as for socketing, hit rating and expertise gems should be used if not capped, else socket agility until you get a minimum of 45% critical strike chance when in cat form, although I personally recommend 47% (I have 49% in current configuration). When this percentage is achieved, armor penetration should be socketed all around.
Generally, I suggest picking up gear with hit and expertise ratings, this is vastly character dependant, and other than that critical strike rating and armor penetration gear, as they proved, at least in my case, to be the best DPS stats, that of course if not taking attack power into account which is the fundamental stat for every melee DPS. Haste is not really required, personally i achieve my dps without it, critical striket rating and armor penetration rating are my main stats.

I hope this post will help anyone who intends to play as Feral DPS using Shred rotation.