South Korean fantasy MMO TERA will be making the transition to the free-to-play model in February, just a little over the one year mark for when the game first launched in South Korea.
As is the usual case in a paid to F2P transition, paid subscribers will be compensated. According to the F2P FAQ that En Masse Entertainment has already drawn up for the coming transition, "If you are a current subscriber to TERA your remaining game time will be converted into elite game time and rounded up to the nearest 30-day mark (explained below). Once your game time runs out, your recurring subscription will automatically convert into a recurring elite subscription for $14.99. If you choose to cancel your recurring subscription, your account will be converted into a founder account at the end of the game time."
The FAQ then goes on to break down the differences between Elite Status, Founder, and Standard accounts. Those with Elite Status will continue to pay their subscription, as detailed above, but will have access to special in-game privileges, such as an Elite Mount (what it is, is to be determined), selected discounts in stores, and daily boosts. Founder Status will be granted to paying players who decide to stop paying subscription and they'll have the privilege of having 8 characters per server as opposed to the Standard's two.
A full list of the changes can be found at the FAQ page on En Masse Entertainment's official site.