Microtransactions are here to stay. We were wary and scared in the beginning -- it was a brave new world, having the gall to ask consumers for a couple of bucks for horse armor. DLC (downloadable content) and microtransactions evolved over time to include better customization, new missions and levels, convenience purchases, and more. The industry began to shape itself around the growing need for better revenue models, as well as conforming to the needs and wants of players while remaining (hopefully) pure in motive.
With the huge success of the free-to-play model in the United States and Europe, a feat which many said was not going to go over too well outside of the Asian markets, paying for your game over time instead of up front has become a staple, an afterthought, to gamers.
World of Warcraft isn't going true free-to-play any time soon, of course. The subscription model works for WoW in a fairly unique way. The number of global subscriptions for WoW make up such a huge, defined income that removing that income from the table in favor of the "5-percenters," the people who presumably pay for items in-game, would be almost criminal in terms of corporate mismanagement -- unless, of course, you could make more money on those 5-percenters than you do on 11.4 million monthly subscriptions, which seems like a hefty move to make.