As I was making the gear guides I wondered what would be the best possible set of gear. I had thought about this before during BC but with so many raids available it was difficult to get a grasp on it. However, as we all know WotLK raiding currently consists of 3 instances. Two of which have a single boss. So here my stab at it.
1. I didn't use any sophisticated math to come of up with the list. I used my general knowledge of the stats to pick which one would be the best for DPS. In that effort I fell back on the general value equation of Hit > Spell Power > Haste > Crit. For this reason you will find a lot more haste items in the list then crit items.
2. I used a Hit cap of 262 to focus my hit gatherings. This assumes you have a shadow priest or are using Imp FF. Alliance Moonkin can take this down to 236, because I assume that they have a Draenei in raid.
3. DPS was the primary factor in ranking items. Mana regen and other considerations were only thought about when two items had very similar levels of DPS stats. This is why you see very little Spirit and Mp5 in the list.
Disclaimer: I am in no way suggesting that this is the ideal set of gear that everyone should shoot for. We all have different priorities and different raiding situations. Plus, this set has over 20% haste from gear alone. I don't know if this level of haste is sustainable with this level of mana regen. I also don't think there are enough weeks between now and when the next content patch drops to realistically have a change to get everything. This list does give me a goal but in reality is probably more of a fantasy.
[Valorous Dreamwalker Cover] - Kel'Thuzad - Naxx 25 - This is Best in Slot (BIS in future) by far. This is not that surprising since it is a tier piece and tier pieces should be itemized for us almost perfectly.
[Valorous Dreamwalker Mantle] - Loatheb - Naxx 25 - The comment for the helm fits perfectly here also.
[Valorous Dreamwalker Vestments] - Four Horsemen - Naxx 25 - If your below the hit cap and don't consider the set bonuses there are a couple of chests that are better. However, the set bonuses are great and I have found many other fine ways to get to the hit cap. Therefore I consider this to be BIS.
[Valorous Dreamwalker Gloves] - Sartharion - Obsidian Sanctum 25 - The chest explanation explains this one perfectly as well, and it completes our 4 piece set bonus.
[Leggings of the Wanton Spellcaster] - Malygos - Eye of Eternity 25 - This is the only deviation from the set bonus and it is so for good reason. It is an item level above most of the Naxx gear and has a ton of Spell Power and Hit on it. Even if you exclude the Hit this item is better then the tier pants. These pants are simply awesome. However, be prepared for a fight to get them. Malygos is not an easy boss like much of Naxx is so you probably won't get as many shots at them as you might for other items. Second, every mage, warlock, and shadow priest in your raid will want these pants. Don't be surprised if you catch some grief for rolling on these, because they are cloth. They are that good.
[Wyrmrest Necklace of Power] - Quest Reward - Heroic Judgment at the Eye of Eternity - While this is technically a quest reward it will not be easy to obtain. First you will have to get [Heroic Key to the Focusing Iris] off of 25 Sapphiron. It starts a quest and is the key to the Eye of Eternity. Most guilds will give this to tanks and guild leaders first to ensure they have access to the zone. After that it will probably be a /roll since it is not an actual piece of loot. After you get the Key you will get the Heroic Judgment at the Eye of Eternity quest. For this quest you will have to kill Malygos. Again this is not easy. This neck is very nice and is BIS even if you exclude the Hit. You can get a slightly worse version of this neck by completing a similar process on the 10 man level.
[Pennant Cloak] - Sartharion + 2 drakes - Obsidian Sanctum 25 - This is probably the best caster cloak in the game. You will be competing with not just DPS for this cloak since plenty of healers will want it also. Also, it is not something you will get a ton of shots at since Sartharion with two drakes up is very tough.
[Bindings of the Expansive Mind] - Instructor Razuvious - Naxx 25 - These are very nice wrists with Hit, Crit and Spell Power. These are the best option for Tauren Druids but Night Elf Druids may want to look at [Unsullied Cuffs]. These don't have any hit or crit, but have more spell power and some haste. However, they will also be difficult to get since they drop off of Sartharion with two drakes up.
[Signet of Manifested Pain] - Kel'Thuzad - Naxx 25 - This is an extremely well rounded ring with a bunch of Spell Power, Haste and Crit. This is by far the best ring available.
[Band of Channeled Magic] - 25 Emblems of Valor - Most of the rings available aren't very DPS focused. A lot of them have spirit or Mp5. So that is how this ring got up here. I was actually pretty surprised when it turned out to me my number two ring. However, If your looking for hit check out [Signet of the Malevolent]. The shear quantity of Hit on this ring will make it desirable for most casters. Don't be surprised if you hear that clothies consider this to be one of their top two rings period. Since it is a Naxx10 drop off of Gothik the Harvester it shouldn't be to hard to get.
[Leash of Heedless Magic] - Malygos - Eye of Eternity 25 - It has a ton of Spell Power and Haste, which make it awesome. Expect to compete with all the clothies for this item.
[Footsteps of Malygos] - Malygos - Eye of Eternity 10 - The great thing about these boots is that you should have very little competition for them. Resto Druids should pass to you since they don't have any spirit and they don't need a lot of Crit or Haste. Since they are Leather, only Moonkin and Elemental shaman should have any interest in them. Anyway, they are a well rounded boot and are perfectly itemized for a moonkin.
[Embrace of the Spider] - Maexxna - Naxx10 - There aren't a whole lot of Spell Power trinkets in the game and this is the only one that has a proc based ability that is good for DPS. However, there are some good trinkets that supply the other DPS stats. If your looking for Crit, Hit, or Haste, you can find better options for this slot.
[Illustration of the Dragon Soul] - Sartharion - Obsidian Sanctum 25 - This trinket is just like the old Darkmoon Faire trinket except that it only works for casters. It won't be as good on fights like Gothek that have a lot of down time, but on more constant DPS fights you can maintain a 260 Spell Power buff. Only a weapon can give you more Spell Power from a single slot.
[Torch of Holy Fire] - Kel'Thuzad - Naxx25 - It is not perfectly itemized for a moonkin. In fact I think it is a little better suited for Pally or Priest healer, but the fact that it has 520 spell power makes it the best in slot. I would live to trade in the Mp5 for some DPS stats so that it looked more like [Wraith Strike] or [Hammer of the Astral Plane], but you can't get around the fact that it has 59 more spell power then the next best weapon available.
[Surplus Limb] - Patchwerk - Naxx25 - There aren't a whole lot of good off hands currently available in the game. A lot of them are really focused on mana regen with Mp5 and Spirit. This item on the other hand is just very well itemized for a moonkin with a lot of Hit, Haste and Spell Power. Plus, you get to carry an arm around with you where ever you go.
[Idol of the Shooting Star] - Instructor Razuvious - Naxx25 - Not hard to guess given that there are very few balance focused Idols currently in WotLK. I picked this idol because Starfire is still my main spell even though I am playing around with Eclipse, and the SF idol helps Starfire a little more then the Wrath Idol helps wrath. What I would really like for blizzard to make an updated version of the [Idol of the Raven Goddess]. I'm still not completely sure that this isn't the best raid idol currently available.
Anyway, that is my WoW Christmas wish list. Most of these items are on top because they are an Item level above most of what you find in Naxx and such, and I have almost no shot of getting all of this but it is something nice to shoot for.