Okay, well I have pretty much mastered how to use this awesome feature now.. I just got done perfecting my shallow water version. Please post what types of editor controls you would like to see made.
So far the few I have on my todo list are:
swamp
trees
cliffs
deepwater
Here is what my shallow water generation looks like.. yes I know there are tons of those little rock things in the water, but it can be adjusted to have only the shallow water tile.
Made this in about 10 seconds: