Warrior (Forums / Skills / Talent Calculator)
Warriors have several mechanics that improve their tanking performance when dealing with multiple foes, as well as their damage output against them. Their damage against packs of creatures, especially when three targets were present, was much higher than other tanking classes. While some variance is expected, it was clear that an adjustment was necessary.
The primary culprits here were Revenge and Deep Wounds:

Revenge now deals 50% damage to a secondary target, and 25% damage to a third target.
Deep Wounds now does 50% less damage for Protection Warriors only.


Paladin (Forums / Skills / Talent Calculator)
One of our goals with our active mitigation tanking model is that you have opportunities to trade significant survivability for more damage when maximum survivability isn’t required. For example, a Warrior could opt to use their rage for Heroic Strike instead of Shield Block or Shield Barrier. This damage gain is intended to be relatively small, and not worth the loss in survivability when actively tanking.

However, for Protection Paladins, this trade-off was much too lucrative. For maximum survivability, Protection Paladins are intended to use Seal of Insight, since it provides a buff to their self-healing, and also provides a significant self-heal on their melee in combination with Vengeance. Unfortunately, when using Seal of Insight, their damage was too low compared to the other tanks. When using Seal of Truth, their damage was too high. So, we’ve increased Protection Paladin damage in general to compensate for Seal of Insight’s relatively low output, while simultaneously reducing the damage of Seal of Truth to bring it into line.

Holy Wrath now deals 100% more damage.
Avenger's Shield now deals 50% more damage.
Seal of Truth and Censure now deal 80% less damage for Protection Paladins only.


Druid (Forums / Skills / Talent Calculator)
Bear tanks have been in a decent place, but we were a little concerned about their sustained area of effect damage. This update to Thrash should address that.

The periodic damage of Thrash (Bear) now deals 60% more damage. Initial direct damage remains un-changed.


Monk (Forums / Skills / Talent Calculator)
We’re really excited about how Brewmaster Monks are turning out. They can still stand a few tweaks though. Their damage, especially AoE damage, was relatively low, and they lacked a way to apply Weakened Blows to a large pack of creatures (which all of the other tanks have).

Keg Smash now deals 50% more damage and strikes all nearby targets, rather than three.
Swift Reflexes now deals 100% more damage.


Death Knight (Forums / Skills / Talent Calculator)
While Blood Death Knights have been higher on damage than most other tanks, we’re expecting that the adjustments we’re making to the other tanking classes will close the gap. While we haven’t made any changes to Blood lately, we will be keeping a close eye on it.

Players no longer require Honored reputation with Mists of Pandaria factions to purchase gear with Justice Points.
The reputation requirement to purchase certain pieces of Mists of Pandaria Valor Point gear have been reduced from Revered to Honored. These include:

Klaxxi - neck items
Golden Lotus - rings
Shado-Pan - cloaks
August Celestials - bracers


The item level of Mists of Pandaria gear that is purchased with Justice Points has been raised from 450 to 458.

The item level of Mists of Pandaria gear that is purchased with Honor Points has been lowered from 464 to 458. As a result, the quality color of these items has been changed from Epic to Rare. However, the PvP Power and PvP resilience of these items has been increased significantly so these items retain their previous degree of effectiveness in PvP.

Mists of Pandaria PvP item vendors were tired of getting the dook kicked out of them. Their health has been increased significantly.

The item level requirement to queue for Mists of Pandaria Heroic dungeons has been reduced from 440 to 435.