The base group now contains the systemd-sysvcompat package. This means that all new installations will boot with systemd by default.
As some packages still lack native systemd units, users can install the initscripts package and use the DAEMONS array in /etc/rc.conf to start services using the legacy rc.d scripts.
This change does not affect existing installations. For the time being, the initscripts and sysvinit packages remain available from our repositories. However, individual packages may now start relying on the system being booted with systemd.
Please refer to the wiki for how to transition an existing installation to systemd.