The forthcoming beta phase will see the existing game world "complemented by huge expanses of ocean." This isn't just for show, as Song says that eventually "oceans will allow players to find new employment, for example extraction, preparation, and delivery of seafood." Sea battles are also mentioned, as are "player-built maritime residences." How this relates to the previously announced underwater gameplay isn't clear, nor is it a given that we'll see all of this in CBT5, but ArcheAge's sprawling open world certainly looks to be putting the "massively" back into massively multiplayer.
There's more to the interview, including bits on action combat and a clarification on Song's previous remarks regarding console games. Hit the link below for the full translation.
[Thanks to Dengar for the tip!]