Blizzard’s 6 November hotfixes mostly correct class tooltips and bugs. The number changes are Voidwalker base health, up by about 40, and the Tanning Rack, which needs skill 125 instead of 140.
Warlocks who lean on a Voidwalker get a sturdier pet at every level, and the Soul Siphon talent no longer lets Wrack feed its own damage. Leatherworkers can reach patterns that need 125 skill without first reaching 140 on the Tanning Rack.
Most of the changes are corrections: tooltips that gave wrong numbers, spells that misbehaved, and creatures, dungeons and quests that did not work. Blizzard also improved how well you can see other players and their targets across long distances. Blizzard says the Bear Form tooltip reported the wrong health increase while the effect itself was right, and that Ravage's tooltip showed a wrong damage value with no change to the damage.
Two items move numbers. Voidwalker base health rises by about 40 at all levels, and the Tanning Rack requirement falls from 140 to 125 so it stops blocking Leatherworking patterns that need 125 skill. Blizzard cut the Tanning Rack’s skill-ups by 15 points to match.
Three class and race fixes stand out. Mages were still learning a Research spell and losing it on relogging, and only Study should exist after the quest. Night Elf Shadowmelded Druids could use Ravage and Pounce, and some Warlock pet abilities were gaining too much from the OrcCommand racial. The Cooldown Manager now shows the full duration of crowd control even when diminishing returns or a stun reduction applies.
The Cooldown Manager now shows the full duration of crowd control at all times, including when diminishing returns or a reduction such as the orc stun reduction applies.
Kaivax
Mages no longer learn a Research spell that should not exist, and 
Arcane Blast lasts 18 seconds
Bloom now heals its target; three 
Druid tooltips are corrected
Ravage and 
Pounce, and 
Orc 
Command stops over-boosting some 
Warlock pet abilities
Soul Siphon talent no longer lets 
Wrack feed its own damage. Leatherworkers can reach patterns that need 125 skill without first reaching 140 on the Tanning Rack.
Night Elf 
Shadowmeld route to 
Bear Form tooltip reported the wrong health increase while the effect itself was right, and that 
Leatherworking patterns that need 125 skill. Blizzard cut the Tanning Rack’s skill-ups by 15 points to match.
Study should exist after the quest. 
Swiftmend
Boot Knife
Rogue
Reckless Swings
Gore Drinker.
Warrior
Skinning.
Restoration
Feral
Affliction
Subtlety
Fury