Systemd 214 offers new file-system sandboxing features, support for new network interface types via networkd, and moves towards state-less system support with being able to rebuild /var if it's empty at boot time. The systemd 214 release also has support for virtualization detect without root rights, systemd-networkd/systemd-resolved/system-bus-proxy now run as their own users, new socket unit features, and much more.
Lennart explained the new state-less system support with being able to rebuild /var as:
What I find the most exciting change: a first step towards a state-less system: we will now rebuild /var if it is empty on boot. My favourite new command line making use of this is:
systemd-nspawn -D /srv/mycontainer --read-only --tmpfs=/var -b
Which spawns an nspawn container, with the directory tree mounted read-only, and an empty, volatile /var mounted on top, that is flushed when you terminate the container. With that in place you can easily run hundreds of ad-hoc throw-away container instances from the same tree, while making sure they don't end up interfering with each other. As next step (planned for the next release): add the infrastructure to support boots with /etc empty, too (or to turn this around: with a tmpfs as root and only /usr mounted in from a read-only vendor tree).
More details on systemd 214 can be found via the release announcement.