I read on: http://docs.moodle.org/en/YUI_menu#Future_Development

"There are no more plans to migrate the YUI menu to Moodle 2.0. Instead, it will be replaced by a similar block that will become part of the Moodle core. A migration plan should be developed."

Does anyone know the status of this or have any further details. Our school uses the course menu block as part of our theme.