Following closely behind the footsteps of the Korean server, the China server for Aion will hold its 4.0 Closed Beta phase on 13th March next month. Published by Shanda Games, the update comes around 4 months after being added in Korea.
The producer for Aion China revealed to the media that throughout 2013, updates for 4.1 and 4.2 will be updated as well. I am guessing these are nothing new, with each update adding 1 of the 3 new classes.
The North American server still has no date for 4.0, although it did kept the community updated of the upcoming new features in store.