Patch 2.4.3 (undocumented changes)

World

 * The first parts for Stormwind Harbor are showing up, you can find the Harbor entrance at the northern canal wall between the Park and Cathedral districts in Stormwind.  and various construction worker NPCs have been added to Stormwind for the Harbor. You can witness the new npcs two of which can open a chat dialog box explaining whats going on and the new construction zone between The Northern area of The Park and Cathedral Square.
 * Tauren Chieftains Band (L70ETC) played a Live Show within the World's End Tavern every hour on July 15th, following the release of Patch 2.4.3.
 * Phase Wyrms from Bash'ir Landing in Blade's Edge Mountains had their numbers in the area greatly decreased and respawn rate seems to be longer. While there used to be a Phase Wyrm for every Smuggled Mana Cell and a few patrols, now only the patrols are there. Making this a less desirable area for farming Motes of Mana.
 * Gan'arg Analyzers are no longer referred as "Simon Unit" in the combat log.
 * Many staircases have been changed to a series of tiered platforms where previously they were ramps.

General

 * Landro Longshot in Booty Bay suggests that the next TCG expansion is titled "Drums of War"; this TCG expansion will include 3 new loot cards: Bear Mount, Party Grenade, Taunt Flag.
 * All non-combat pets have had their levels changed. Depending on the level of the area they can be obtained, their level may vary from 1 to 70. Pets from Stormwind and Orgrimmar orphanage quests are level 1, and pets from Shattrath are level 20. Netherwhelps summoned using Netherwhelp's Collar are level 20. Disgusting Oozeling are level 55. High level pets from instances and Quartermasters are level 70.
 * Players new to the game have better access to the tutorial system. A pop-up frame will hint them to it.
 * Haris Pilton is no longer part of the Lower City faction.
 * The Brewfest and Hallow's End holidays were tested on the PTR, and both have received some changes. Some of the changes include the Great Brewfest Kodo and the Swift Brewfest Ram dropping from the new boss, Coren Direbrew, located in Blackrock Depths during the event. Crashin' Thrashin' Racer Controller will be a gift during Winter Veil.
 * A new mini-pet,, can now be redeemed by people who attended the Worldwide Invitational 2008 in Paris.
 * New loot available from the World of Warcraft Trading Card Game has been added.
 * The icons for Dark Whelpling and Tiny Emerald Whelpling have changed. All whelplings now also make a sound when clicked on.
 * Gear swapping also cancels a wide variety of non spell actions as well. Using a mount is not canceled, but most actions with a progress bar (opening a chest, quest items with a gear cursor, etc) are canceled. Hotfixed that instead of cancelling spells you are not allowed to swap gear or move items around bags while casting most spells, but as previously, mounting is exceptional that you can do it while casting mount spells.
 * The animation for a Warlock's Ritual of Souls has been changed to show the soulwell falling from the sky, and upon consumption all healthstones or the limit of the soulwell's duration, it despawns in a very noticeable flourish.

PvP

 * Epic gems are now available for arena points: Bold Ornate Ruby, Gleaming Ornate Dawnstone, Inscribed Ornate Topaz,Potent Ornate Topaz, Runed Ornate Ruby, Smooth Ornate Dawnstone. These versions are not Unique-Equipped.

Enchanting

 * Void Shatter's casting time has been reduced to 3 seconds.
 * Enchant Weapon - Deathfrost can now proc on Lightning Shield, Consecrate and other dot effects such as Insect Swarm

Fishing

 * Schools now sparkle while Find Fish is active.

Tailoring

 * A new tailoring pattern, Pattern: Dress Shoes, is now available from Haughty Modiste in Tanaris.

Raids and Dungeons

 * Don Carlos in heroic Old Hillsbrad Foothills drops a new hat Don Carlos' Famous Hat which summons and dismisses your very own Coyote Spirit!
 * Druids are no longer taken out of Aquatic Form when swimming to Coilfang Reservoir. There is also no more breathable area inside that big tube you are swimming in.

NPCs

 * New quest NPC Don Carlos and his White Stallion have been added just outside Gadgetzan graveyard in Tanaris. He offers Nice Hat... where players need to defeat his old self in the Caverns of Time within the Old Hillbrad instance.
 * Tamed Warp Stalker at Area 52 in Netherstorm had its name changed to Warpy.
 * Change to NPC's Enrage and player's Enrage-like abilities sound effect (Bloodlust sound effect) reverted from 2.4.2.
 * Technician Halmaha is no longer attackable by players that choose to align themselves with the Scryers, this was probably a bug to begin with, it might have been considered harassment since it involved killing a repair vendor many people, from both factions used.
 * Level 70 Elite Tauren Chieftain now play a live show each night at 8 pm in the Grim Guzzler.
 * An arena vendor, Griz Gutshank has been added to the Grim Guzzler.
 * A new NPC, the Dark Iron Brewer, can now be found in the Grim Guzzler. If you talk to him repeatedly he will pass out drunk, and drop his stein on the ground. You can loot it to get some Dire Brew, that will turn your character into a Dark Iron dwarf for one hour.
 * Cro Threadstrong now sells apples for you to crush.

Items

 * The Stoneskin Gargoyle Cape now has the flavor text "It's white and looks longer than your average cloak or cape." to acknowledge the popular meme.
 * Noble's Elementium Signet is sold by Qixdi Goodstitch in Booty Bay.
 * Elune Stone's duration has been increased back to pre-Feb 2008 levels.

User Interface

 * (Partly documented) The cooldown rings in the buffs and debuffs now have a small yellow line.
 * Whispers from GMs are now prefaced with a small blue "Blizz" logo.