how about a Biome challenge? like the sky limit contest there would be a specific world to download and that would have every biome type mapped out in it (all the biomes would have to be the same size, say 100 by 100 blocks or 50 by 50 (superflat world)) and it's "pimp my biome" the idea is for the player to make each biome as nice and creative as possible they can use terraforming/organic and structural, the entries would be judged on : creativaty, skill, originallaty and how "biome spacific" they are (<how they fit their buildings into the terrain and wether they suit the biome)
I think this idea could use some refining but it could make for some interesting results.
what do you guys think?