I will tell you what I would like it to be. Maybe it gives you a Visual Studio-style editor for websites, which let you easily lay out a page, edit CSS, add event handlers to elements, link to other pages, and make and use data bindings (which could be configurable: persistent to DB, associated with user account, validated with this function, etc.)
Then you could use the data model created by the bindings, modify it if you want (data model specification is probably integral to everything), add and configure whatever extra stuff is supported (accounts, websockets, whatever).
A cross between Weebly and Visual Studio. It would be great for demo apps and internal utilities.