At URL I committed a working systemd unit, without chroot support, which is better than nothing. I also removed the CPU parameter from conf.d/named, which I find quite useless and impossible to easily support inside systemd units.
I will commit in a week if nobody disagrees. Thanks
+ 13 Jul 2013; Pacho Ramos <firstname.lastname@example.org> +files/generate-rndc-key.sh,
+ +files/named.conf, +files/named.service, bind-9.9.3_p1.ebuild:
+ Install unit file (#466158)