My God It's Full Of Stars And Also Money
Blizzard up until this point has pretty clearly insisted that all items being upsold on their item shop were cosmetic in nature only. Today that distinction blurred a bit: for $25 you can buy the fastest mount in the game for all your characters.
You do need to have previously unlocked a super-fast mount in-game to unlock the fastest speed possible, and you'll still need to have paid for the actual skill to use the mount, which is by far the most expensive part of the equation. Still, this is actually a concrete item to be used, as opposed to a vanity pet that follows you around.
Expect the line to be blurred a bit more. Especially since at the moment, there's actually a queue to give Blizzard $25 to get a Edward Cullen-sparkly mount.
No. Really.
Yes. Over $600,000 worth of orders for a sparkly virtual mount, waiting in line patiently...
(When learning this, I immediately heard the plaintive cry "It's for my girlfriend!" shortly thereafter. Uh HUH.)