the game has 6 complete biomes:
Meadows, Black Forest, Swamps, Mountains, Plains and Mistlands.

there are two more biomes coming : Ashlands and Deep North. They may also upgrade the ocean biome.

i would wager the game is 90% feature complete and 70% content complete. There is currently about 100+ hours of content available.

since they are committed to no paid dlc i would expect few if any dlcs and minimal updates once the game is finished.