Blizzard opened up pre-orders for World of Warcraft: Battle for Azeroth today. The upcoming expansion is slated for release "on or before" September 21, 2018. Those who pre-order will get immediate access to the quest lines that lead up to the new expansion.

Pre-orders also gain access to four of the six planned Allied Races coming with Battle for Azeroth. These races include the Highmountain Tauren, Lightforged Draenei, Nightborne, and Void Elves. It also includes a boost to level 110 for a single character. There are also some additional items included with a more expensive Digital Deluxe version.
Declare Your AllegianceEarly access to Allied Races
Pre-purchase Battle for Azeroth and begin your quest to recruit four new playable Allied Races. Heroes of the Horde can enlist the Highmountain Tauren and Nightborne, and champions of the Alliance can add the Lightforged Draenei and Void Elves to their ranks.

Explore two fabled kingdomsPlunder the islands of the Great SeaCharge into a WarfrontInfuse your armor with titanic mightBoost to level 110
Enter the raging conflict between the Horde and the Alliance prepared to survive on the front lines of a vicious new war.

Digital Deluxe Edition
World of Warcraft Mounts
Ride proudly astride the Seabraid Stallion mount as you fight for the Alliance, or prove your allegiance to the Horde with the Gilded Ravasaur mount. No matter the battle or adventure, you'll be ready.

World of Warcraft Baby Tortollan Pet
Whether you're fiercely battling other pets or simply want to put your feet up on its sturdy shell, Tottle the baby Tortollan pet's got you covered.

Overwatch goodies
Show your faction pride on the battlefields of tomorrow with Horde- and Alliance-themed voice lines for Torbjorn; emotes for Tracer; Anduin, Jaina, Sylvanas, and Saurfang sprays; and Kul Tiran and Zandalari player icons.

Hearthstone card back
The Azeroth is Burning card back will add firey style to your favorite Hearthstone decks. Just be sure not to set the whole board alight!

StarCraft II sprays
With new Horde and Alliance sprays, you can cover the map as you conquer your foes.

Heroes of the Storm mount
Prowl into the Nexus with your new Primal Flamesaber mount. With three color variants (Green, White, and Toast) you'll ride into battle in style.

The standard version is just $49.99 (USD) while the Digital Deluxe is $69.99. Do note that the store has been hammered today so you may be met with a lengthy queue and wait time just to get through to the purchase screens.