classes section:

Death Knights

Army of the Dead: The cooldown on this ability has been reduced from 20 minutes to 10 minutes. Army Ghoul damage dropped by 50%. Cannot be used in Arenas.
Raise Ally: The cooldown on this ability has been reduced from 15 minutes to 10 minutes. Cannot be used in Arenas.
Rune of the Stoneskin Gargoyle: There is now a 1-handed version of this rune in addition to the current 2-handed rune.
Rune Strike: Threat generated by this ability increased by approximately 17%.
Talents
Unholy
Night of the Dead: Now reduces the damage your pet takes from area-of-effect damage by 45/90%, but no longer applies to area-of-effect damage caused by other players. In addition, this talent now reduces the cooldown of Army of the Dead by 2/4 minutes, down from 5/10 minutes.
Scourge Strike: Redesigned. The base ability now deals 50% weapon damage plus an additional amount as physical damage. However, for each disease the death knight has on the target, the target will take additional shadow damage equal to 25% of the physical damage done.
Unholy Blight: This talent now deals only 10% of Death Coil damage as a damage-over-time effect on the target.
Druids

Prowl: This ability no longer has multiple ranks and penalizes movement speed by 30%.
Rebirth: The cooldown on this spell has been lowered from 20 minutes down to 10 minutes. Cannot be used in Arenas.
Rejuvenation: The base duration on all ranks of this spell is now 15 seconds.
Tranquility: The cooldown on this spell has been reduced to 8 minutes, down from 10 minutes.
Talents
Balance
Eclipse: This effect will not activate again within 15 seconds of either type of Eclipse effect firing, in addition to the existing 30-second cooldown for each type of Eclipse. In addition, Eclipse now grants a 40% critical strike chance to Starfire and 40% increased damage to Wrath, up from 30%.
Force of Nature: Health on the treants has been increased.
Feral Combat
Predatory Strikes: The Predatory Swiftness buff from this talent now has an 8-second duration.
Restoration
Gift of the Earthmother: Redesigned. This talent now increases spell haste by 2/4/6/8/10% and reduces the base global cooldown of Lifebloom by 2/4/6/8/10% instead of its previous effects.
Pets
Avoidance (passive): Now reduces the damage your pets take from area-of-effect damage by 90%, but no longer applies to area-of-effect damage caused by other players.
Hunters

Call Stabled Pet: Cooldown reduced from 30 minutes to 5 minutes. Cannot be used in Arenas.
Deterrence: Now also increases the chance for ranged attacks to miss the hunter by 100% while under its effect.
Misdirection: Redesigned. Instead of having finite charges, it now begins a 4-second timer when the hunter using Misdirection performs a threat-generating attack, during which all threat generated by the hunter goes to the friendly target. In addition, multiple hunters can now misdirect threat to the same friendly target simultaneously.
Talents
Beast Mastery
Intimidation: If the hunter's pet is in melee range of its target, the stun from Intimidation will now be applied immediately instead of on the pet's next swing or attack.
Pets
Avoidance: This talent has been replaced by Culling the Herd. Hunter pets now innately take 90% less damage from area-of-effect abilities like all other class pets. This does not apply to area-of-effect damage caused by other players.
Cower: Redesigned. This ability no longer affects threat, and instead reduces damage taken by the pet by 40% for 6 seconds with a 45-second cooldown. While cowering, the pet's movement speed is 50% of normal speed. Cower now only has a single rank and is available at pet level 20.
Culling the Herd: This pet talent has replaced the Avoidance talent in the pet trees (Hunter pets now gain that benefit automatically without expenditure of talent points). Culling the Herd increases pet and hunter damage by 1/2/3% for 10 seconds each time the pet deals a critical strike with Claw, Bite, or Smack.
Demoralizing Screech: The attack power reduction from this ability has been increased by 40%, equaling the maximum possible attack power reduction from the abilities of other classes.
Improved Cower: Redesigned. This ability now reduces the movement penalty of Cower by 50%/100%.
Pet Leveling: Hunter pets now need only 5% of the experience a player needs to level, down from 10%.
Venom Web Spray: Range increased from 20 yards to 30 yards.
Web: Range increased from 20 yards to 30 yards.
Wolverine Bite: This talent is now enabled when the pet lands a critical strike rather than from the target dodging the pet's attacks. In addition, this talent no longer has a prerequisite.
Mages

Talents
Arcane
Arcane Empowerment: This talent now also grants 1/2/3% increased damage done by the mage's party or raid for 10 seconds after the mage gets a critical strike with Arcane Explosion, Arcane Missiles, Arcane Barrage, or Arcane Blast. This effect is exclusive with Ferocious Inspiration and Sanctified Retribution.
Fire
Blast Wave: The mana cost of this talent has been significantly reduced.
Burning Determination: The duration of interrupt immunity granted by this talent is now 20 seconds.
Dragon's Breath: The mana cost of this talent has been significantly reduced.
Firestarter: When this talent is triggered, it makes the next Flamestrike cost no mana in addition to being instant.
Improved Scorch: The debuff from this talent no longer stacks, and instead can apply the full effect from a single cast of Scorch.
Frost
Deep Freeze: This spell now deals a large amount of damage to targets permanently immune to stuns. In addition, when this ability deals damage it will no longer consume two charges of Fingers of Frost for those mages with the Shatter talent.
Fingers of Frost: This talent now triggers immediately on casting a spell rather than being delayed until the spell strikes the target.
Pets
Avoidance (passive): Now reduces the damage your pets take from area-of-effect damage by 90%, but no longer applies to area-of-effect damage caused by other players.
Mirror Image: Health on the mirror images has been increased.
Water Elemental: Waterbolt mana cost reduced by 80%.
Paladins

Divine Intervention: This ability now also removes Exhaustion or Sated from a target if the recipient is out of combat when the effect ends. In addition, the cooldown on this ability has been reduced from 20 minutes to 10 minutes. Cannot be used in Arenas.
Flash of Light: This spell no longer causes a heal-over-time effect unless the player has the Infusion of Light talent.
Lay on Hands: This ability will place Forbearance on the paladin if used on his or herself. It will not place Forbearance on others.
Talents
Holy
Aura Mastery: This effect of this talent has been reduced in duration to 6 seconds.
Infusion of Light: This talent now causes the paladin's Flash of Light spells to heal the target for 50/100% of the Flash of Light healing amount over 12 seconds.
Protection
Divine Guardian: This talent no longer increases the amount of damage transferred to the paladin from Divine Sacrifice. Instead it causes all raid and party members to take 10/20% reduced damage while Divine Sacrifice is active. In addition, the duration has been changed to 6 seconds, however the effect does not terminate when Divine Sacrifice is removed before its full duration.
Divine Sacrifice: Redesigned. The effect of Divine Sacrifice is now party-only and the maximum damage which can be transferred is now limited to 40% of the paladin's health multiplied by the number of party members. In addition, the bug which allowed Divine Sacrifice to sometimes persist despite reaching its maximum damage has been fixed. Divine Sacrifice will now cancel as soon as its maximum damage value is exceeded in all cases. Finally, damage which reduces the paladin's health below 20% now cancels the effect early.
Retribution
Repentance: This crowd control effect will no longer break early from the damage done by Righteous Vengeance.
Priests

Divine Hymn: The cooldown on this spell has been reduced to 8 minutes, down from 10 minutes.
Power Word: Shield: This spell can now be cast on non-raid/party friendly targets.
Talents
Shadow
Improved Devouring Plague: This spell now deals 10/20/30% of its total periodic effect instantly, up from 5/10/15%.
Mind Flay: The range of this ability has been increased to 30 yards, up from 20.
Shadowform: This talent also now causes Devouring Plague and Vampiric Touch to benefit from haste. Both the period length and the duration of these spells will be reduced by haste. In addition, the mana cost has been reduced from 32% to 13% of base mana.
Vampiric Embrace: This talent now provides a 30-minute buff that cannot be dispelled, instead of a target debuff and only generates healing for single-target shadow damage spells.
Pet
Avoidance (passive): Now reduces the damage your pet takes from area-of-effect damage by 90%, but no longer applies to area-of-effect damage caused by other players.
Rogues

Deadly Poison: In addition to its existing effects, when a rogue applies Deadly Poison to a target which has already reached the maximum number of applications, this will also trigger the poison which the rogue is using on his or her other weapon.
Dual Wield: Rogues now know this ability upon logging into the game at level 1.
Stealth: This ability no longer has multiple ranks. While active, the single rank of this ability (available at level 1) allows rogues to move at 70% movement speed.
Talents
Assassination
Improved Poisons: Bonus chance to trigger Deadly Poison from this talent increased.
Murder: This talent now provides a flat damage increase of 2/4% against all targets, instead of only targets which do not appear in Icecrown.
Subtlety
Preparation: The cooldown on this ability has been reduced to 8 minutes, down from 10 minutes.
Filthy Tricks: The cooldown reduction this talent provides for Preparation has been reduced to 1.5/3 minutes, down from 2.5/5 minutes.