When Blizzard launches its fourth World of Warcraft expansion, the panda-themed Mists of Pandaria, on September 25, it will be putting another nail in the coffin of retail-based game distribution.

In addition to a standard digital edition, offered at a same-as-retail $39.99 price point, Mists of Pandaria will be the first WoW expansion to also come in a $59.99 Digital Deluxe edition, which includes the kinds of in-game perks that were previously only available in the retail Collector's Editions. The Digital Deluxe download will come with a flying mount, a Lucky Quilen Cub pet, exclusive portraits for use in Starcraft II, and banner sigils for use in Diablo III. Standard edition downloaders will also be able to obtain these perks later for an additional $20 purchase.

Blizzard isn't totally abandoning fancy retail packages. The $79.99 retail Collector's Edition of Mists of Pandaria will also include a behind-the-scenes DVD and Blu-ray, a soundtrack CD, a collectible art book, and a mouse pad, as well as the in-game perks. But by offering the coveted, exclusive virtual items to downloaders at a price point lower than the retail Collector's Edition, the company seems to be acknowledging that some of its most devoted players no longer want to be weighed down with physical products to play an online game.

Mists of Pandaria could provide a welcome boost to WoW's subscriber numbers. While the game still leads the MMO segment, holding stable at just over 10 million subscribers throughout 2012, the game has fallen from its peak popularity of 12 million subscribers in May 2010, a phenomenon one producer attributed to the launch of Bioware's The Old Republic late last year.

We checked out the Mists of Pandaria beta earlier this year and found it to be an enjoyable if somewhat overly familiar return to WoW's roots.