"Planet Minecraft Contests We have monthly community contests with themes, judges and prizes, pixel art trophies and recognition! Above all else, contest are simply meant to be fun."
They should probably change the description on the contest page, then xD
Oh my, a heavenscape/dreamscape world would be incredible.
Have build-able clouds or a cloud block, could act like soul sand where you sink into them more psychedelic things and colours.. or minerals like opal that could be animated to slowly change colours like prismarine... I think of the diamond block and ore in the Loafcraft texture pack - http://imgur.com/FtiG5lb