Warlords of Draenor is the fifth upcoming expansion to World of Warcraft. It was officially announced on Novemeber 8, 2013 at BlizzCon.
New Features
Draenor is the homeworld of the Orcs, Outland before it was shattered, and the heart of the Draenei.
Warlords of Draenor will raise the level cap from level 90 to 100.
New player models.
You will be able to build your own base, called Garrison.
Added new Toy Box and Heirloom tabs.
New world PvP zone, called Ashran.
Seven new dungeons and two new raids will be released with the expansion. Heroic difficulty is now called Mythic.

The Darkmoon Faire will now feature Moonfang, a new boss. Moonfang has a low respawn time, and can be tagged by anyone, and will give you an extra 10 tickets on your first kill.

Patch 5.4 - Siege of Orgrimmar is now live on all servers.
New Features
Siege of Orgrimmar - get ready to fight your way to Garrosh by reading the encounter journals and watching guides.
Timeless Isle - all new area awaits you, with new world bosses, account bound epic items, new rares and pet battle tournament.
Flexible Raid Difficulty - designed for pre-made groups of 10 to 25 players or any number in between. This means it's possible to have raids of 15 or 22 players! Difficulty will adjust automatically based on the number of players present with encounters intended to provide a challenge roughly between Raid Finder and Normal difficulty.
Proving Grounds - is a way for players to practice new specs and get better at their current spec in an environment that doesn't inconvenience other players.
Connected Realms - will connect low population realms into groups to form a single Connected Realm.
World Changes - Orgrimmar and the Vale of Eternal Blossoms have seen some significant changes in Patch 5.4!
Ordos and the August Celestials - new world bosses.

The new patch brings a new raid, many class changes, a new PvP season, and a whole new questing area. It also marks the end of the Battlefield: Barrens event.
Patch 5.4 - Siege of Orgrimmar recap on the week of the release.

Along with all of the other Siege of Orgrimmar loot, Patch 5.4 adds some Heirloom weapons that drop from Garrosh. These items do not drop in Raid Finder difficulty, only Flex, Normal, and Heroic. Keep in mind that nothing on the PTR is final until it goes live.
New Features
Multiple Raid Finder Queues - will finally allow you to queue for multiple Raid Finder wings at once.