A smooth upgrade path from 'scripting' to 'structured application' is also a concern of the Zope 3 developers, albeit it hasn't had that much attention yet.
I don't think Zope 3 is that heavy on object modelling. Zope 3, as Zope 2 has, encourages designing with objects, true, but connecting a new view consisting of a page template and a few python snippets to an existing content item is something I imagine a scripter will want to do. I don't think that requires a large amount of modelling. Customizability is what Zope 3 is all about.