In a somewhat shocking announcement, Neowiz has announced the termination of RaiderZ Korea, with the game and website closing on 24th September 2013, with cash reimbursement going on through October. This follows closely after the Europe server announced its closure as well.
While I personally see the main cause being TERA going Free-to-Play, with the same concept but better executed, I guess RaiderZ was simply not up to the challenged put forward by its main competition. There is no word if the game will revive under another publisher.