Having these events would make Classic applications more "up to date": You could let the user drag & drop documents in views in order to reorder them.
Of course the developer would need to write the code to change the items to reorder, but having the the events and information (which document(s) was/were dragged, and where were they dropped) would make that possible.
The drag&drop event could use the UnprocessedDocuments- Property to get the dragged documents and -like PostDragDrop- Event of NotesUIDatabase- an identifier for the target (NoteID of the target document or name of the target category where the documents where dropped).
These function could be even used in default templates: The Policy- precedence in the domino directory could be realized using this new function.
Also reordering rules in the mail- template or the server configuration would not need the "sort"- buttons anymore.