A creative game developer has worked out a way to incorporate Minecraft builds into his game, turning the blocky builder into a level editor of sorts.
As you can see in this short video, the developer, r00nk, is able to place blocks into a configuration that matches the level size in his game Back Into Orbit (a cutesy, retro-looking isometric shooter), and then very easily import them (in the video it happens instantaneously).
This is how it works, according to r00nk's comments in the related reddit thread:
In order to make the in game buttons do commands, I use a server wrapper which searches for the docmd keyword. It's important to note that this is somewhat insecure, because anyone who writes "docmd(banana)" can make the server execute the "banana" command, so don't try this at home kids, unless you know you'll be the only person on the server.
r00nk can only export and use levels made with certain types of blocks, not the full arsenal of what Minecraft has available. It's still an impressive feat, especially if you take it as a proof of concept. If you could get this working on a large enough scale or with enough ease, it could be one of the smoothest level creation tools since the days of Warcraft III.
Game development, especially at the indie level, is as often about what's fun and interesting as about what's efficient, and r00nk has definitely shown some serious chops here.