Teleportation effects (at least with regards to outdoor Northrend areas) now cause a loading screen to appear, instead of just instantly moving you to the new location (with accompanying loading lag). This is true for hearthstones, and quest teleports like the K3 teleporter.
Weapon skill points can no longer be gained from attacking mobs that are immune to combat.
Performing a /kiss command on Mojo will no longer increase your buff size on a mount, but instead will dismount you and transform you into a frog.
The racial restrictions was also lifted from the pre-Patch 1.4.0 epic mounts, instead of excluding these. This was likely a blanket approach to all mounts to save time, as including nor excluding the old mounts would change what races have them.
Hail to the Chef is now obtainable, since The Northrend Gourmet no longer requires you to cook the nonexistent Shoveltusk Soup and Succulent Orca Stew, and three new recipes have been added.
Tenacity effect has been lowered. Now improving your health, healing, and health regen by 18% (down from 25%) and increasing your damage dealt by 14% (down from 18%).
Restricted Flight Area duration increased from 8 to 9 seconds.
Contrary to the official patch notes, the cooldown on Howling Blast has not been removed. It has been reduced from 6 seconds to 5 seconds. The tooltip doesn't explain this, but if you try to hit Howling Blast twice in quick succession it will not work.
Necrosis adds 20% Shadow damage instead of 10% for melee attacks.
The level requirements for gathering professions that were removed in the last patch have been reinstated, which should prevent abuse of abilities such as Toughness for Mining (all ranks of which now give Stamina rather than hit points).
Alchemy
[Lesser Flask of Resistance] has been added. Resistance to all schools of magic by 50 for 1 hour. Guardian and battle elixir. Persists through death.[2]
All Eternal Transmutes cast times have been reduced to 5 seconds (from 25 seconds).[2]
Leveling cooking up to 450 is now easier, with the recipes for [Gigantic Feast] and [Small Feast] being yellow all the way to 450 instead of going green at 437.
[Enchant Weapon - Executioner] now permanently enchants a melee weapon to occasionally grant you 120 armor penetration rating. (Old - occasionally ignore 840 of your enemy's armor.)
[MOLL-E] is now rare, has had the cooldown reduced to 8 hours (down from 1 day)[6], and lasts for 10 minutes. Also, it can now be put into an Engineering bag.
[Nitro Boosts] effect duration reduced to 2 seconds (from 5 seconds), cooldown reduced to 3 minutes (from 5 minutes).
The FishingDaily Quests near Shattrath no longer give the quest fish on the first cast, requiring the original multiple casts to fish up the quest item.
[Pygmy Suckerfish] drop rate is now greatly increased. In schools of fish, the drop rate appears to be up to 75%.
[Glyph of Death Grip]: When you deal a killing blow that grants honor or experience, the cooldown of your Death Grip is refreshed. (Old - Increases the cooldown of Death Grip by 10 sec but stuns targets for 1 sec.)
[Glyph of the Ghoul]: Your Ghoul receives an additional 40% of your Strength and 40% of your Stamina. (Old - Your Ghoul receives an additional 20% of your Strength.
[Glyph of Icy Touch]: Your Icy Touch generates 10 additional runic power. (Old - Your Icy touch damage is reduced by 10% while generatign additional 10 runic power)
[Glyph of Obliterate]: Your Obliterate strikes for 20% additional weapon damage. (No longer decrease bonus damage per disease)
[Glyph of Raise Dead]: Your Raise Dead spell no longer requires a reagent. (Old - You generate 20 runic power whenever you summon a ghoul)
[Glyph of Rune Tap]: Your Rune Tap heals yourself for an additional 10% of the effect, and also heals your party for 10% of their maximum health. (Old - Didn't benefit the DK and only healed the party)
[Glyph of Unbreakable Armor]: Unbreakable Armor grants an additional 15% armor. (Old - Unbreakable Armor grants an additional 5% parry chance but no longer increases your Strength.)
[Glyph of Flash of Light]: Your Flash of Light has an additional 5% critical strike chance. (Old - Your Flash of Light heals for 50% less initially, but also heals for 140% of its inital effect over 12 sec.)
[Glyph of Blessing of Might]: Now properly augments the duration of all spell ranks (it previously did not affect Rank 6).
[Glyph of Holy Light]: Your Holy Light grants 10% of its heal amount to up to 5 friendly targets within 8 yards of the initial target. (Hotfixed after patch release)
[Glyph of Renewed Life]: Your Reincarnation spell no longer requires a reagent. (Old - All stats increased by 5% for 1 min when you Reincarnate.)
[Glyph of Windfury Weapon]: Increases the chance per swing for Windfury Weapon to trigger by 5%. (Old - The attack power bonus on the additional attacks granted by Windfury Weapon is increased by 40%.)
The Achievement frame's summary display has been split into two parts: One for the Achievements tab, another for the Statistics tab. The bottom half of the achievement tab's summary now displays how many achievement points you have earned from each category.
All portrait menus options which previously disabled themselves when the actions were not available (such as Trade, Grant a Level, Follow, Duel, Summon Friend, Inspect) are now always selectable from the portrait menu, providing a HUD display of why it won't work when the eligibility criteria has not been met.
Ready Checks have been reverted to make sound once again.
[Enti's Quenched Sword] Now requires the user to be at least level 70. Previously could be enchanted and sent to low-level alts, enabling the wielder to one-shot enemies many levels higher than the user.
[Preserved Holly] and [Preserved Brewfest Hops] can now be used while not mounted and instead of changing your mount until you dismount, give you a 1-hour buff that automatically changes your mount.
The guards in Booty Bay are now level 77 (up from 67).
Brittle Revenants in Storm Peaks gained two new abilities: Mace Smash (short knockdown & spell interrupt) and Shield Bash (prevents spell casting from that school for about 8 seconds).
The 'Steel Gate Flying Machine' in Howling Fjord has a new model, the engineering rare mount from [Flying Machine Control], complete with all movement usability of the mount.
Mounts can now be used in the formerly "indoor" area where the Nexus, Oculus, and Eye of Eternity portals are located.
Dungeons and Raids
It has been reported on many discussion boards that the 'safe spot' in the chamber of Heigan the Unclean in Naxxramas has been removed.[9]
Elder Nadox can no longer be kited safely up the stairs and away from his protectors. If he is kited, he will enrage with a five-minute Berserk buff and deal 25-30k damage per hit (on heroic).
The range of the Spell Disruption ability of Heigan the Unclean is increased to 30 yards.
The elite blue dragonflight Squads from the portals in Violet Hold now split into two groups.
The bosses in AQ, Onyxia's Lair and Zul'Gurub have had their cash drops significantly reduced (about 50-70%).
In The Oculus, dropping off the side of one of the rings will now kill you instantly (previously, you would zone out to the instance portal). Verified at least on the lowest ring.