The korean developer, XL games, laid off a chunk of the korean dev team last fall. The game has been out for a while now in Korea (a bit under 2 years) and the last patch, "1.0", seemed to take the game backwards according to some players - you can google around ArcheAge 1.0 patch to see what issues people have, but I think its been said a bunch of times that a lot of the 1.0 changes may/will not make it into the NA/EU Trion published game since it sort of made the game more casual and less sandbox-y/PVP.
The bigger problem is that XL games is hard at work on Civilization Online, which should start beta testing this summer. Its been their main focus for the past 2 years after ArcheAge flopped in Korea, and will be an Asia-only game (for now). TERA suffered a similar problem, the game wasn't a big success in Korea so the korean dev team really slowed down on new features and patches after a while, which screwed the other regions.
That said the game does have now 2+ years of content behind it, so I'm sure it'll be a great launch and really fun for a long time, especially given its sandbox nature. Everyone who played the f2p Russian version liked it.