Looks really neat. If you are interested, I did this simpler effect for Marco Gubert,(someone gave me a hand with it) which can look basically like a carbon copy of the A5/A6 detail mapping. Maybe you can find it somewhat useful...

Code:
/////////////////////////////////////////////
// Give your Terrain 2 Skins
//		Skin 1 - The texture (non-tileable)
//		Skin 2 - The detail map (tileable)
//
///////////////////////////////////////////////////

function mtl_terraintex_init(){

// Adjust the texture transform to do some tiling of the textures
mtl.matrix11 = float(8);	// default u scale 
mtl.matrix22 = float(8);	// default v scale
}

material mat_terrain_detail
{	
	event = mtl_terraintex_init;
	
	effect = "
	
	matrix matMtl;
	
	texture entSkin1;
	texture entSkin2;
	
	technique t0
	{
		pass p0
		{
			Texture[0] = <entSkin1>;
			Texture[1] = <entSkin2>;
			
			TextureTransformFlags[1] = Count2;
			TextureTransform[1] = <matMtl>;
			TexCoordIndex[1] = 1;

			ColorOp[0] = Modulate2x;
			ColorArg1[0] = Texture;
			ColorArg2[0] = Diffuse;
			
			ColorOp[1] = AddSigned;
			ColorArg1[1] = Texture;
			ColorArg2[1] = Current;
			
			ColorOp[2] = Disable;
			AlphaOp[0] = Disable;
		}
	}";
}


//////////////////////////////
//WED action for Terrain:
//////////////////////////////

action ffp_terr_detail
{
	my.transparent=off;
	my.material = mat_terrain_detail;
}


cu

--Eric