GraPhiX: That would be great
Variation map: Red circle.
Blue star: Textures used in the variation mix.
Green star: Hard edge slot.
After you select a variation map, everything will be painted for you , try to make some water and see how the sand on the beach is painted on the fly, also notice the grass in the editor/screenshot how it gives you variations.
If you already painted your level , it will NOT overrule this but use your own painted terrain. To get the procedural/variation effect you must then remove what you painted by using SHIFT while painting terrain.
best regards Preben Eriksen,