I'm not new to gentoo thorugh sabayon, although my skill level is fairly minimal, anyways, my first suggestion would be to include iptables support by default, so that a proper firewall can be set up. Many people consider linux simply because they hear of security benefits, but firewalls should be used regardless of OS if you're connected to the net. This should be deployed in the standard release of sabayon.
The second one I'd recomend would be a release focused entirely on security, perhaps built around the hardened-sources, in the same vein as the bio-edition. The obvious setbacks are that hardened-sources are a long way behind in development then vanilla-sources/gentoo-sources, so many people will lose a great deal of hardware support.
The second proposal there I feel is more a nice option, but simply that. The main hope of this proposal is the inclusion of a firewall into the standard release of Sabayon.