In reply to valendesigns.

@valendesigns in a previous WP Tavern post, Nick Halsey's proposal clearly stated that it was his goal that the Customizer would replace the menu admin.

Menu Customizer Tentatively Approved for WordPress 4.3

The specific bit of the quote reads

"If the Menu Customizer provides all of the features of the existing menu management screen, while clearly demonstrating that it is a better solution than the existing screen in user tests, it could potentially replace the existing screen entirely for users that can access the Customizer"

To me, that indicates adopting the Customizer for menu management, then eventually phasing out and removing menu management from the current admin system.

If I'm reading that incorrectly, or if more posts have been made that clearly state otherwise, please please please provide links!