In point of fact, Google has something almost identical in the form of the Compatibility Definition Document, which gives fairly strict and detailed specificati

In point of fact, Google has something almost identical in the form of the Compatibility Definition Document, which gives fairly strict and detailed specifications for what an Android device is. There's also a set of tens of thousands of automated tests that an Android implementation has to be able to pass to be considered "Android." And to date, no one has really made "fundamental" changes in how the interface works - the only major mover out there is sense UI, and it still uses the same widgets and framework.