After a recent change to the /etc/rc structure (rcorder etc...), having :
cups_enable="YES" in your /etc/rc.conf makes my system unbootable. The error msg is similar to:

Starting rpcbind.
ELF ldconfig path: /lib /usr/lib /usr/lib/compat /usr/X11R6/lib /usr/local/lib /
usr/local/lib/compat/pkg
a.out ldconfig path: /usr/lib/aout /usr/lib/compat/aout /usr/X11R6/lib/aout
Starting mountd.
Starting nfsd.
Starting apache2.
Usage: cups {reload|restart|start|status|stop}
init: can't get /dev/console for controlling terminal: Operation not permitted

Adding a comment in front of the line in /etc/rc.conf still doesn't make FreeBSD boot for some reason, but manually moving /usr/local/etc/rc.d/cups.sh to /usr/local/etc/rc.d/cups.sh.notworking now allows BSD to boot, but with the following message:

Starting rpcbind.
ELF ldconfig path: /lib /usr/lib /usr/lib/compat /usr/X11R6/lib /usr/local/lib /
usr/local/lib/compat/pkg
a.out ldconfig path: /usr/lib/aout /usr/lib/compat/aout /usr/X11R6/lib/aout
Starting mountd.
Starting nfsd.
Starting apache2.
Usage: cups {reload|restart|start|status|stop}
Starting SAMBA: removing stale tdbs :
/var/db/samba/connections.tdb
/var/db/samba/locking.tdb
/var/db/samba/messages.tdb
/var/db/samba/sessionid.tdb
/var/db/samba/brlock.tdb
Starting nmbd.
Starting smbd.
Starting local daemons:.

(Notice how cups still shows its usage flags).

Running /usr/local/etc/rc.d/cups.sh start manually works fine.