Alloy 1.6 will support defining an ActionView via XML markup. Note that you must set the showAsAction property to force the item onto the ActionBar or you'll get an empty "row" in your menu.
See the sample app supplied with
ALOY-1098 or refer to this code. If you include the collapsible_action_view flag as shown, tapping the item's icon will expand the view. You can then tap the "home as up" button to collapse that view.
This is supported on Android 3.0+