Oh by the way even if you are not into Minecraft...
http://forum.unity3d.com/threads/after-playing-minecraft.63149/
That forum discussion is absolutely brilliant from start to finish. As a person messing with terrain I suspect you might enjoy reading through that as much as I did.
It spans 6 years so far... and it is a forum I return to a couple of times a year to see if people added anything new, and sometimes to reread portions of it just for fun.
RE: Procedural Terrain Generation: Making a TerrainSquare