I think this program is a great idea! One thing I would suggest is to add some keyboard shortcuts to allow people to operate the program using the keyboard only. Windows Explorer has this: in the navigation pane, you can go up or down using the up/down arrows,
and you can expand/collapse a folder using the left/right arrows. It would be great if you could implement that in WDE as well, should be pretty simple. Also, a keyboard shortcut for switching between the two explorers would be essential.