Here is my particular use case, though I think this feature would be beneficial to many people.

For simplicity and templating, all project folders have a main document called Project Documents where we keep all related project documentation. The problem is, when a document is created in another located and I need to move it to the project folder, the list of options I see are all named Project Documents. The only way I know which is which is that I have to close the window, open the document is want it to be moved to, and then return to the doc I want to move and then select the first option listed (I've figured out that it lists the most recent first.)

It would be so much easier if the "Move to" option showed me spaces, folders, and existing docs in the same hierarchy - much like it does if you are trying to move a task.