When we talk about Avalon, we often talk about integration and unification, the notion that the Avalon framework unifies any type of UI you seek to paint to the screen, whether its 2d, 3d, layout, text or video.  Integration and unification describe the experience for the designer/developer, but that doesn't speak to the experience of the end result.  I like the term convergence as a different way to describe that from the perspective of the final product, the application, the user experience.  It is the experience of seeing these different media converge into a single application that is serviced by the underlying unification, both in the Avalon rendering and compositing engine and the Avalon development framework.