We are testing this on PC-BSD right now, should be in the next 11.0 images we roll in April. However to manually try it out, apply the patch and add some entry like the following to your /etc/rc.conf
fastboot_enable="YES"
fastboot_rc_early="/usr/local/etc/rc.d/pcdm /usr/local/etc/rc.d/hald /usr/local/etc/rc.d/dbus"
(pcdm is our graphical login manager, replace with gdm or whatever you use)
Questions, comments, suggestions, all appreciated so we can refine this!