Well, I'm not sure I want them to write the Rulebook for anything, the more competition and the more variety the better, but one sure thing, I do like the looks of the apps redesigned to stick to the new set of conventions for their "Material Design". It somehow combines the minimalism and simplicity of the "Flat UI" fad with the more sophisticated aspects of more modern interfaces.

I wish I could get a taste of it on my Nexus 4 with Android L but I guess that's not happening.