Most unimplemented terrain between zones has been filled for a seamless flying experience, with new mountains, lakes inaccessible by foot, and other filler terrain introduced. Rough jarring shifts in textures in areas not supposed to be accessible by foot have been smoothed over.
Unimplemented terrain south of Ahn'Qiraj has been removed, and the new coast goes directly around the cliffs surrounding Ahn'Qiraj. The coastal cave still remains.
Astranaar has been updated with new high-resolution textures.
The Talondeep Path has been excavated away by the Horde, creating a new passage between Ashenvale and Stonetalon Mountains: the Talondeep Pass. To the northwest is a new night elf outpost: Stardust Spire.
The previously unnamed and empty night elf house near the Felwood border is now named Orendil's Retreat.
Tree models have been updated with a higher quality ones.
With the arrival of the goblins, the entire zone has been terraformed and carved into a giant Horde symbol. New locations created by the goblins include:
Steamwheedle Port has sunk under the sea, along with a large chunk of the land at the northeast until Gadgetzan, which has been converted into a port.
The Uldum gate in the Valley of the Watchers has changed in appearance significantly, and now leads to a dungeon area. There is now also a second, overland entrance to the partially-implemented Uldum zone.
The inaccessible land west of Burning Steppes has been replaced by water. Intentionally or not, it means that it now matches the Deeprun Tram, which passes underwater between Stormwind and Ironforge. The split continues further west as a rift in the crust between Dun Morogh and Searing Gorge, and then between Badlands and Loch Modan.
The zone has been updated with new high-resolution textures.
Pyrewood Village and the Greymane Wall have been updated to use Gilnean architecture. Pyrewood Village is now connected by a bridge to the shattered gate of the Greymane Wall.
The Forsaken buildings have been updated to the new Northrend-style Forsaken architecture.
The entire city has received a graphic update with new high-resolution textures. Areas formerly clipped have been implemented with the advent of flying in Azeroth.
The Command Center and SI:7 no longer have narrow corridors leading to them, and are now located on a green meadow outside the Old Town. Oddly enough, the locations of the two buildings have been swapped. The Command Center now also has hunter trainers and Justice/Valor Point vendors inside it; Master Wood has been moved outside.
The entrance to Stormwind Keep has been revamped, and now features a statue of Varian Wrynn and overlooking balconies.
Dragon claw marks are visible on the two towers at the end of the Valley of Heroes. Trollbane's statue has been destroyed while the others have fallen into the water next to the bridge.
The boat that previously connected Stormwind Harbor to Auberdine now goes to Rut'theran Village.
Genn Greymane now stands next to Varian Wrynn in the throne room.
A bank and an auction house have been added to Dwarven District. This has the potential of making this district an alternative hub to the crowded Trade District.
Low-level inks can no longer be traded for Ink of the Sea but now for Blackfallow Ink. However, since the ingredients for this ink aren't available before the release of Cataclysm, low-level inks can't be traded right now.
The [Flight Master's License] (previously known as Azerothian Navigation) is available at level 60. It allows flying in Azeroth and costs 250 gold.
Master Riding is available at level 80. It allows flying at 310% speed and costs 5000 gold (without reputation bonuses).
Smart mount macros are broken because all of Azeroth is now marked as flyable.
Some, but not all, flying mounts are now usable in Azeroth as land mounts - this seems to be mostly crafted mounts such as Tailor-made flying carpets and Engineer-made flying machines. The mount operates only as a land mount, unless in water, where you will be unmounted like on a flying mount.
Is it possible to mount up and fly on a flying mount when swimming at the surface of water.
Character creation screens for gnomes and trolls have been updated with new backgrounds, featuring the Gnomeregan surface and Echo Isles respectively.
The Azeroth world map, maps of Kalimdor and the Eastern Kingdoms, and most old-world zone maps have been updated for the Cataclysm changes, and now feature a different visual style reminiscent of TBC/Wrath maps.
The PvP interface has been updated to support rated battlegrounds. It also allows creating an arena team without visiting an arena master.
Relics can now be used for multiple classes, but the name of the respective classes must be listed in their tooltips. All existing Idols, Librams, Sigils and Totems (as Relics) are now renamed Relics.