Shaiya Online, Choirock’s online games division was acquired by Nexon Co., Ltd., a worldwide leader in free-to-play online games. The acquisition includes the MMORPG itself.
Shaiya Online, currently published in 16 countries worldwide, supports an online community that engages in a detailed, deeply entertaining storyline told through large scale battles containing up to 1,500 players fighting with another 1,500 players at once, and allows players to quest for more than 1,000 glories.
Nexon is planning to support the game’s already strong following in North America and Europe, as well as expanding Shaiya’s presence by leveraging Nexon’s global resources.
Nexon North America is currently hosting 8 free-to-play online games:  Dragon Nest;  Vindictus ("Mabinogi: Heroes");  MapleStory;  Sudden Attack;  Combat Arms;  Mabinogi; Dungeon Fighter Online; and  Atlantica Online. With 3 Facebook games:  MapleStory Adventures;  Zombie Misfits; and  Wonder Cruise.
UPDATE 2012/02/18: Aeria Games, the current publisher of Shaiya Online in North America posted the following in their forums:
Aeria Games has received inquiries from our players on the acquisition of Shaiya Online and the development team by Nexon from Choirock Games. Aeria Games will continue to be the publisher and operator of Shaiya in the Western markets and the transaction should not in any way affect the operations of the game or the servicing of our players and community.- Aeria Games
You can also read the Press Release of Nexon here, in PDF format.