I do wonder how much effort and forks will be required to keep Gentoo, well, Gentoo going forwards, as more and more stuff either is either lumped into Systemd or depends on/assumes its presence.

One can already see how you at least have to keep the libsystemd package installed on Debian's latest, even if you use something other than systemd as the init etc, or else apt throws a tantrum.

http://ewontfix.com/15/ may be the most interesting read in all this. Notice how everything but dbus and the systemd lib have various issues. And if kdbus hits the kernel, systemd is poised to position itself as the mediator between (legacy) dbus and kdbus.

All in all there is some serious "one true way"-ism coming out of the systemd camp.