From the Official Pet Store FAQ
us.blizzard.com/support/article.xml?locale=en_US&articleId=29845

Does this mean you'll be introducing more services like this in the future? Will you be introducing the ability to buy epic weapons/etc. in the future, for example?
As with the pets, mounts, and other items players can obtain through Loot cards from the World of Warcraft Trading Card Game, Pet Store pets are purely cosmetic and just for fun. Like other paid services we offer, such as Paid Name Changes, Race Changes, and Character Re-Customizations, the Pet Store service is entirely optional and intended to provide players another means to enjoy World of Warcraft in a way that isn't detrimental to the game and that doesn't detract from the gameplay experience for players who choose not to use the service.
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The part that stands out for me is the last part "...to enjoy World of Warcraft in a way that isn't detrimental to the game and that doesn't detract from the gameplay experience for players who choose not to use the service."

They will not start selling gear/weapons

PS - Finnicks won that debate, well done sir