The thing is that in real world, almost all of the non-metallic materials have some (even if tiny) amount of SSS, and from the picture comparison, to me it looks like lambert model is better at fooling eye into believing the material has tiny bit of SSS going on since shadow falloff is softer. In reality it would be crazy to make everything in your (for example interior) scene covered by SSS materials.
I am all for it, but i would not replace Lambert with it. For example Vray and MR have a roughness parameter next to diffuse, which blends Lambert with rough Oren-Nayar model. So perhaps corona could have one that blends between Lambert and Full moon :)
