The Amani Dragonhawk is a new flying mount available right now in PTR 4.1. It will be obtainable from a WoW TCG: Twilight of the Dragons loot card and redeemed at Landro Longshot in Booty Bay.
The TCG expansion is likely to be on sale around August-November range to coincide with the novel by Christie Golden — World of Warcraft: Thrall: Twilight of the Aspects. However, no official release date for the TCG expansion has been announced.