While on many init systems adding modules to autoload lists is problematic, systemd provides a very easy way to do that. What's needed is just to place a file containing three lines of needed modules: vboxnetflt vboxnetadp vboxdrv in /usr/lib/modules-load.d/virtualbox.conf. The ebuild message should also comment how manual adjustment is unnecessary if systemd is used (or perhaps detect it and supress the message). Note it might be good to load the modules immediately on merge with `systemctl restart systemd-modules-load`.
+ 17 Nov 2013; Pacho Ramos <pacho@gentoo.org> +files/virtualbox.conf, + virtualbox-modules-4.3.2.ebuild: + Install a modules-load.d file to load modules automatically on systemd + (#490988 by Rafal Rzepecki) +