Add snappy package system support
Ubuntu is pioneering a new packaging format called Snappy: https://www.ubuntu.com/desktop/snappy
It would be great to get this supported and implemented in WSL's Ubuntu - the important bits to support in the WSL Kernel I believe are AppArmor (http://wiki.apparmor.net/index.php/Main_Page) equivalents which are built into the Linux Kernel as an optional item to add Mandatory Access Controls.
In userland, snapd needs to be running via Systemd, so background daemons potentially need to be added.
Erkin Alp Güney commented
snap and flatpak require btrfs.