Description:
When systemd is running in the initramfs it complains that these targets are missing: local-fs.target, swap.target, timers.target, paths.target and slices.target . It also complains about a socket: "systemd-journald-dev-log.socket".
According to the bootup man page [0], the boot process up to the basic.target is identical in both the actual boot and the initramfs boot. Some of these targets are also listed there.

[0] http://www.freedesktop.org/software/systemd/man/bootup.html

Additional info:
* systemd 216-3, mkinitcpio 18-2
* base and systemd as hooks in mkinitcpio

Steps to reproduce:
Boot with systemd as your initramfs init. Check logs:
ut 08 11:01:10 localhost systemd[1]: Cannot add dependency job for unit local-fs.target, ignoring: Unit local-fs.target failed to load: No such file or directory.
Out 08 11:01:10 localhost systemd[1]: Cannot add dependency job for unit swap.target, ignoring: Unit swap.target failed to load: No such file or directory.
Out 08 11:01:10 localhost systemd[1]: Cannot add dependency job for unit timers.target, ignoring: Unit timers.target failed to load: No such file or directory.
Out 08 11:01:10 localhost systemd[1]: Cannot add dependency job for unit paths.target, ignoring: Unit paths.target failed to load: No such file or directory.
Out 08 11:01:10 localhost systemd[1]: Cannot add dependency job for unit slices.target, ignoring: Unit slices.target failed to load: No such file or directory.