The idea is to make it easier to work directly with individual objects on the screen. So instead of calling up a Class Hierarchy Browser, you might say, "Bring me the family tree of this class, arranged on the screen to look like a tree," and the objects will just sorta slide into place. You'll also be able to create "ad hoc" poses - "Remember the arrangement of morphs on the screen now."
The result, I hope, will be an environment that makes you feel like you're really getting your hands directly on the objects, rather than using "tools" to manipulate them like we do today.