The first Closed Beta Test started in November 2011 in Korea and lasted a few days.
The second Closed Beta Test started in October 2012 in Korea and lasted a few days too.
Open Beta Tests started in November 2012 in Korea and lasted a few weeks.
The first Free to Play server opened in Korea in December 2012.
no official information yet about the European release
The SEA (South East Asia) Region has his own publisher Asiasoft. Estimated release date Summer of 2013 in SEA.
Europe and other regions probably have to wait till 2013-14 to play the game.
Find out more: Release Date Discussion