I'm glad to see the Up button but I don't think we can ever expect to see the start menu back unless sales are so bad that they begin to seriously reconsider it.
the back and forward buttons on nearly all mice works faster to navigate the folders unless you're at the top level and you can't go up.
the up button was there in windows 8 since the beginning when milestone builds were leaking on net. forget start menu. microsoft will never add it again.
Saw this up arrow but never used so far, lately recognised, you can navigate with ALT+Arrow left/right to...