I have updated the UML object model for Tintagel in line with revision 8 in the Tintagel source repository:

I added Nodes, Content Types, Fields, Field Values and Data Types. The idea behind Tintagel is to have a really clean object model without a lot of little exceptions like the ones that can be found in Drupal where the number of database tables storing content data gets larger by the minute. To that end Tintagel will have Nodes to represent content and everything will be a node (menus, comments, everything). Nodes will have a Content Type. Content Types will have Fields that have a Data Type describing the sort of data in the field. Nodes will contain Field Values that point back to the Content Type.

Those familiar with Drupal will see the ideas behind the Views and CCK modules coming through in the Tintagel core.