New mounts in Patch 6.2.2 (and beyond).First of all, Draenor flying is here! Hopefully you've already completed Draenor Pathfinder and are now soaring through the skies. With this patch there are three new mounts already available now, with three more coming later in the year.
Available right now:
The stunning Heavenly Azure Cloud Serpent is the reward for the newest mount collection achievement, Lord of the Reins. It requires you to have 300 mounts on a single character (presumably excluding class mounts).
Two mounts are purchasable from new Timewalking vendors. These require a new currency, Timewarped Badges, which are earned in Timewalking dungeons (during Timewalking Dungeon Event periods). The purple Eclipse Dragonhawk is sold by Cupri in Shattrath, and the ghostly blue iron horse - the Ironbound Wraithcharger sold by Auzin in Dalaran. The vendors are only present during the Event periods.
Coming later in the year:
A new yeti mount, the Minion of Grumpus will be related to the Feast of Winter Veil in 2015. We're not yet sure of its source.
Our Legion Collector's Edition mount reward has been revealed! The Illidari Felstalker is based on the new Felstalker model introduced in 6.2. It will have a matching companion pet.
Armory update bug updates...
The Felfire Hawk and Voidtalon of the Dark Star are now showing up on the Armory, so you no longer have to manually add them to your collections. Unfortunately, however, the Brown Horse and Swift Warstrider seem to have vanished from the Armory around the same time and now require manual flagging (see their individual pages to add them to your collection). The Chauffeured Mechano-Hog and Acherus Deathcharger have not changed status and also remain missing.