Hari K T has a new post to his blog that shares his concern about a "design flaw" in the component/package methods promoted by Symfony2 and Zend Framework 2:

Looking from outside both Symfony2 and ZF2 is full of standalone components. But the reality is not the same. Though Symfony2 components are split into each components in github, you cannot give a pull request to that component. The tests for all the components still resides in the core.

He points to the Aura framework project as a good example of how to make a truly component-centric set of tools complete with tests bundled into the component's download right next to the source.