Most people would agree that making the menubar moving left and
right is not an acceptable solution, so explaining what would
you do in the maximized case is essential.
Why couldn't the same solution work for maximized windows as well? The
only difference being the presence of the close, minimize and maximize
buttons to the left of the global menu when a window is maximized. Sure,
this would cause the menu to shift over to make room for the window
buttons, but would this really be so much of a distraction to people?