In preparation for the November release of Warlords of Draenor, Blizzard will roll out a substantial patch for World of Warcraft come October 14. Patch 6.0.2, or 'The Iron Tide', ushers in a wealth of new content and fixes including skills and ability updates for all classes. It also includes the long-promised character model updates, as well as a host of UI improvements and tweaks so numerous you'll need to make a cup of tea before you peruse them all.
There's also a new Iron Horde Incursion world event, which Blizzard has rather melodramatically set the scene for below:
"The Dark Portal in the Blasted Lands has turned blood red. Hundreds of strange-looking orcs are violently pouring into Azeroth, killing everything that stands in their path. Nethergarde and Okril’lon have already fallen, and while the Horde and the Alliance moved as quickly as they could to get reinforcements to their people, they are too late. The Iron Horde invasion has begun."
Additionally, a "revamped" five-player version of Upper Blackrock Spire will be available to level-90 players for a limited (but unspecified) period of time.