Announced in 2011 under the codename Project R1, Tree of Savior is developed by the original team that developed Ragnarok Online.
http://treeofsavior.wikia.com/wiki/Tree_of_Savior (This wiki also has every information about the game revealed by the developers so far. More information will surely come after its official launch.)
Unlike RO, moving around in TOS is keyboard-based. Attacks and support skills have distinct areas of effect and there's no targeting (unless you're an Archer class).
They recently announced the Korean publisher for TOS, so an international CBT is predicted to be in either 1 or 2 years from now.
We're not sure if there will be a guild system in the game, so if we do establish a guildbase in TOS, communications will be mostly external from the game.