A couple of observations:

1) We're so not there right now

2) Have you ever thought it's weird that in english, we capitalize the proper name of something/someone/somewhere, which you might think of as the instance of a particular class of things, but the popular programming convention is exactly the other way around?

There are a few more cases I'd like to see addressed:

Components

class Component_App extends Component {}
class Component_Formz extends Component {}

Abstract and extending classes

// abstract base class
abstract class FormzDriver {}
 
// extending classes
class FormzDriver_Doctrine extends FormzDriver {}
class FormzDriver_FormDB extends FormzDriver {}

Note that they aren't necessarily namespaced by their component (i.e. Formz_FormzDriver_Doctrine... this could get ugly really fast), but they're namespaced by what they do. Much like Component_Formz is namespaced by what it does.