latest version in portage: 1.9.0 source at http://www.cse.unsw.edu.au/~neilb/source/mdadm/mdadm-1.11.0.tgz or http://www.kernel.org/pub/linux/utils/raid/mdadm/mdadm-1.11.0.tar.bz2 or http://source.rfc822.org/linux/utils/raid/mdadm/mdadm-1.11.0.tar.bz2
done
Thanks!