Since I don't wanna spam forum with level editor suggestion im gonna use this thread. First idea, waterfall tool this could be used to make really nice rivers and would make for some cool routes. Built bulk height map creation, it would be awesome if there was a tool built into the editor where you could create the height map for the whole terrain including macro without having to use third party software such as world machine or l3dt. Built in mesh creator/editor, Again this would take place of third party software such as blender this would come with a built in texturing ability as well. A much easier way of creating a new map, you would use the new ap option and then you would get the option to name map, choose thumbnail, and edit the files this would be available at any time with a option in the menu.
Not happening, for the painfully obvious reason that tools like World Machine or Blender take years and years to make.
I don't mean exact copys of blender and world machine I mean much more simplified versions, you can still use those programs for more advanced height maps and meshes but it wouldn't take years to make simplified version plus the basic programs themselves for blender and world machine did not take years maybe 1 year at most.
To make a waterfall, you model it in blender as a plane that has been curved and subdivided into the shape of a waterfall. UV unwrap it and make sure the uv map is rectangular and the edges are on the bounds. Make or find a seamless waterfall texture that has transparency. Import the model into a map. Create a texture that has alpha transparency and the waterfall texture applied. In the animation section you could give the texture a looping pan animation. There ya go!