You can found a first WIP patch for the new Neos.MediaBrowser here:
Any comments highly welcome on the github PR if it’s related or here for more general discussion.
@aertmann @sebastian The PR is more or less done, the backend module is now fully in the MediaBrowser package, if you can check the PR and comment if you think something else need to be done for the first step, share your thought 
Hopefully there is not too much left over in the Neos and Media package, but that need also to be carefully reviewed.