We have The Ocean (unfinished), The Ashlands, and The Deep North, the latter 2 being completely barren right now, and the Ocean only partially completed. If it's anywhere along the same timeline as the last major update, about 2 years. If they use some of those fat profits they made off this game, then I could see The Ocean being done in a few months, but lets not kid ourselves :)

If they drip feed random foods, graphical tweaks, cross play optimization, and event themed furniture for the next 12 months, the game will probably die off completely though. I hope they operate with a little more urgency with the next round of updates, and focus on adding fun, engaging content.

The ocean could be polished off with some more enemies to fight (Kraken please), deep sea fishing (new rod), maybe a new boat or two (fishing boat?), update the swimming system?(its time IG). Since some of it's already been done, I'd assume this would be the next biome they try to tackle, but maybe they wanna take another 2 years an craft Deep North or Ash lands...who knows.