Please consider allowing the center top mouse 'scroll' wheel to traverse through menu items.
It's hard to explain, but if you look at the feature in Microsoft word 2007, it will be clear...
Essentially, when you use the wheel, rotating down will traverse menus to the right, rotating up will traverse menus to the left. The cursor must be hovering over a menu item (for the wheel to work), as that item will be focused, but not necessarily selected.
Notice that this feature is somewhat non-traditional and Microsoft obviously sees value in it... but the main benefit is the ability to use the center mouse wheel to peruse through menu items.
Clarification: 'not' through menu items, but across the menu bar.