One thing that is a constant problem for me is that depending on the order in which I implement classes, abstract classes; and interfaces I don't always have the same ability to move/copy javadocs.
When things are done in the structured way of create interface, then implement abstract class, then concrete class everything works well with the javadocs propagation options.
So I would it be possible to have some kind of refactoring that allows to move or copy the javadocs from an "overridden"/implemented method up and down the inheritance tree.
What about concatenating all the docs in a method inheritance tree? Sometimes I need to I quickly document an interface and need to pull in details from multiple implementations.
I know this is a little strange... but documentation never happens at the prescribed time and place, and having the ability to refactor/move/copy the javadocs would really add to my ability to do just-in-time documenting :)