I just wonder is this is interesting:
Also, as for OO... I have messed a bit with eZ Publish cms and I really liked their content management. It's something like our custom fields, but with several additions:
- each custom field type has it's own mini-template depending on the content. A textarea field would have a mini-template with simple textarea html block, but e.g. a "flv media" custom field (used for storing the path to media file) would have a template with a html flash player code. The mini-templates would have two versions: one for page.php and one for list.php
Those mini-templates get automatically included into a skeleton template of a page (or other content type). Our page structure is like title, subtitle, text, - eZ Publish approach is much more flexible. Without any need to write a plugin, we can extend a page, adding there more data fields with their own representation mini-template. Now we just include a tag and display raw data, something like I describe is only in page.add and page.edit templates.
(I think I can make a plugin that illustrates this idea.)
Also, we have only "page" content type. Ez publish allows to define more content types, like e.g. "blog page". In this process we define the skeleton template for it (we can copy the skeleton template of page), and define the data fields used (with their mini-templates) and their order (like title, subtitle, text, podcast field->displaying an mp3 flash player). In eZ we can even create a content type "contact form" and add there data types of several input fields and a textarea.
This functionality could do wonders without much coding. Now if we want to have something extra, it must be a plugin. With the above system, somebody could even make a gallery if he was stubborn enough, making a content type "gallery page", adding three data fields: title, image, description, and voillea: the fundamental image showing page is ready. Several such "gallery pages" in a category list would make a simple gallery category (remember that there are also data type mini-templates for list.php).
I encourage you to install and try eZ Publish to see it. However, eZ Publish is a bull full of code and I don't like its exagerrated complexity (like their own template language). Anyways, I'm sure that this content type management can be achieved with less effort.
For this content system, I would only see additionaly the change in PFS and change in Auth system (per-user permissions). It's neccessary since if the data fields are about to show the files, the files must be saved somewhere.