This was onlyat in previous news.
Community manager Zarhym posted, "We are currently exploring the possibility of adding a way for players in certain regions to make purchases directly within the game. As part of this process, elements related to this will be appearing on the PTR. We’ll provide additional updates on our plans as development progresses."
The possibility was revealed when a public test server showed an item for a future patch that adds as 100% XP buff for killing monsters and finishing quests in an "In Game Store".
Blizzard hasn't been shy about macrotransactions, such as the $25 USD special mount.