Good to hear that Apple is still working on its "real" operating system.
There are still some issues left:
- OpenGL 4.x Support.
- ZFS or another modern filesystem.
- NUMA support in the kernel for multi-socket systems like the Mac Pro.
- Updated Unix tools! Some of the CLI commands are very outdated because the upstream switched over to GPLv3 and Apple is still using the last available GPLv2 licensed version.
- Better software management: We still lack a reliable (and easy) way to uninstall installed software. I have seem some "Uninstaller.app" files bundled with the actual application and once I even had an "uninstall.sh" within the .dmg file.

- Support Suspend to Disk while external drives are connected.
I don't expect this, but I would welcome a (Linux-like) package management system like dpkg/apt-get or rpm/yum. If Apple doesn't want to do it they could at least give some support to the MacPorts or Homebrew projects. And please, please donate some of your infinite money to the FreeBSD project.