My idea for minecraft is that you can mis-match between the versions of structures, for example: you like the new villages, but hate the new oceans, you can choose if you want reworked structures/world generation.
You will be able to choose what version of structures you want in individual worlds, to create a better version for those who dislike some changes to the game.
You should be able to change all this in the world generation settings when starting a world.
You also should be able to remove certain structures altogether I.E: desert villages.
This... would actually be kind of cool. I personally like the new world generation, but I'm sure for many players it would be amazing to be able to select different types of world generation- if, for example, you wanted more recent mods with older world gen. (...On that note, whatever happened to custom worlds? Terraforged is fantastic, but I sort of miss being able to mess around with sliders.)