Hi, where is the need to have separate sections "Briefcase" and "Documents". I have heard from a lot of users, that they would prefer to have Documents and Briefcase combined. And basically, they are the same. Briefcase can contain all files and be accessed by webdav, Documents can only contain text files/notes/tables.
The best would be to combine both and only offer an edit option for files created with the "new" option.