Only one sub-menu can be open at once (by design). There is currently an issue with z-ordering of menus. The latest registered top level menu has it's flyout menus on top. Maybe the child flyout menus should be registered on show instead of at create time. that would put all flyout menus on top of main menus.
top level menus that are open at all times do not get focus by tabbing since they are just links. But if you click on a top menu item, you can then use all 4 arrow keys, page-up, and page-down to navigate in that menu.
A toolbar with flyout menus on click of buttons. Toolbar flyouts appear directly under the toolbar item that opens them. Or if there is no room below, the flyout opens above the toolbar item.
Bug: The sub-menu under 'Bing' does not show up using keyboard shortcuts, it works fine on standalone flyouts above.
Issue: the menu item that has a custom handler associated does not trigger the select event on the menu when it is selected. Since the user is then handling that item click separately, is this ok? Or does select need to fire also?
misc text to push toolbar right