Some thoughts...
The word test should be changed to "click here to type".
Also, the overview box should hava some sort of starting view, not an empty blue thing stickin g out there, underneath the menu.
Also, there should be an option for "smaller menu icons and titles" because the overview box gets pushed too far below. I'm on a 13" MacBook. Forget tablets and netbooks...
Nice, the "n" keyboard shortcut, just figured it out.
However, it seems to stop at that. Consider using keybindings for navigation as well.