Looks great! I especially love that the concept you are calling StreamFields is finding its way to more and more CMS's (Concrete5 and Perch call them "Blocks", ExpressionEngine and Craft call them "Matrix Fields", and Advanced Custom Fields for Wordpress calls them "Flexible Content Fields"). It's really a great balance between giving site owners the ability to manage rich content on a page while also giving designers the ability to ensure that content sticks to the site's overall design.