The next expansion to World of Warcraft, Mists of Pandaria, is coming on September 25, 2012, and pre-sales have been opened for people who want to be ready to play on launch day.
And, like recent Blizzard releases, the Digital Deluxe and Collector's Editions will include in-game content for games other than Mists of Pandaria; Diablo III players get an exclusive banner sigil and accent, and StarCraft II players get the infested orc and night elf Templar portraits.
The Standard Edition of Mists of Pandaria, available for $39.99, and the Digital Deluxe Edition, available for $59.99, are both available for pre-purchase on the Battle.net site. For full details about how to pre-purchase, the items included in the Digital Deluxe Edition, and prices, see this Battle.net post.
Battle.net - Mists of Pandaria Launches September 25, 2012