May need some changes in list view for 2.4
A file system interface
Selecting a folder enables some actions
Selecting a file enables other actions
A combo box from Windows Explorer showing a hierarchy on left and flat view of one folder on right
A hierarchical view from MacOSX file browser
A paneled view from MacOSX file browser
|A view from Blackboard
It seems that Blackboard looks more like the way Sakai used to be, with 'add' buttons at the top in the actions bar, rather than by the folders, and no tree view. I notice that they've called WebDav 'Web Folder' - interesting in view of the debates that there have been lately about renaming it to make it intentionally more obscure, rather than less!
Slightly different - but a view from Flickr showing all files (here, images) along the bottom of the screen, with the 'folders' (here, sets) at the top
See attachments for screenshots from Google Groups, which are looking at this in a radically pared-down approach