1.7 is supposed to be the biome update. What we currently know is that it is going to add new features to the current biomes (mostly oceans) and that they're probably going to add a few new biomes. Post below what you think they should add in The Biome Update. I think they should add:

1. Underwater Ruins (Such as sunken ships.)

2. Some of the old biomes are added in (Gravel Beaches, Savannahs, Rainforests, etc.)

3. Biome Specific Caves (Caves in snow biomes are not going to look exactly like caves in jungle biomes, for example.)

4. Ores spawn more commonly in some biomes (Like for example, diamonds might spawn more often in a mushroom biome than in a plains biome.)

5. More Biome Specific Structures (Snow Temples, Ocean Temples, etc.)

6. Biomes look more realistic (Jungles have really tall grass, extreme hills have snow on the top of each mountain, etc.)