My proposal for @red51 revolves around a more customisable world generation tool, will explain in a bit what I mean exactly but I first need to provide my reasons behind this suggestion/request.
Often enough I find myself looking for a specific type of terrain e.g. a lake that has a snow biome to its east and a savannah biome to its west, or a big mountain canyon that starts from a beach and ends on a lake or a desert. So instead of looking through 10s of random seeds until I find what I want I propose a customisable world generator in which you would be able to specify the spawn biome as well as a few biomes around it to be whatever you like, then the rest of the world outside would be randomly generated as with the current system.
So this is how I propose this system to work:
You get a small grid (I would prefer a 5x5 grid) where each gridbox represents a biome e.g. for a 3x3 grid:
| Biome 1 | Biome2 | Biome 3 |
| Biome 4 | Biome 5 (Spawn) | Biome 6 |
| Biome 7 | Biome 8 | Biome 9 |
Then you select what you want these biomes to be (if the grid background changed colour for each biome you select that would be useful too) e.g. on a 5x5 grid:
And finally this custom world would be generated for you 
