Biomes as in "different kinds of terrain generated" would be possible even now, but the problem is that current MineCraft client calculates its own biomes (and there's no way to replicate that in MCS) and so precipitation (rain vs snow vs none at desert) is handled on the client rather than by the server. Also for the swamp biome the client darkens grass, again, without any consultation of the server.
I just hope the biomes would be sent in the new version's protocol, not just "be stored in the save files"
I just hope the biomes would be sent in the new version's protocol, not just "be stored in the save files"