This is a brilliant idea! Has this project been abandoned in favor of other projects?
I would be very much interested in seeing progress in this utility. It was also mentioned hat there was a possibility of generating the minecraft map on the fly to allow for 1:1 Minecraft block to in game DF tile? That sounds like an awesome idea to me that could sort out a lot of the complaints about ugly rivers or how DF forts couldn't be generated alongside the map itself due to scale differences. Even if that isn't a possibility any more, work on the original utility would be much appreciated.
Some ideas moving forward could be:
Biome selection based on the biome, vegetation, temperature and evilness maps and support for custom biomes like those from ExtraBiomesXL or BIome 'O Plenty.
More cave generation functionality? Things like multiple cavern layers, where these layers begin and end, height, width and density of these layers, percentage of floor to be mycellium being set for each layer (with the possibility for 0% and 100%).
Toggleable tunnels on top of caverns? (MC tunnel generation on top of the caverns)
Toggleable Lava lakes at y-level 12? (for those who need lava in the overworld)
Less blocky generation due to scale differences, generate curves to bridge random blocky terrain borders.
If you are willing to allow another access to the source code, I wouldn't mind helping / trying out these ideas? (but depending on the language, my input may be minimal)