A project to explore the world a great deal, exposing many clearly defined biomes. There are a few glorious deserts as well as one proper plain. Of course, many forests, possibly a few rainforests, but those are really quite indistinguishable from the denser temperate forests. Let's hope there is more eye-candy and rainforest-type canopy in the future to help diversify all the biomes!
Yes, save the rainforests, even in Minecraft.