Systemd 209 does land the Kdbus code, which as reported earlier on Phoronix should be merged into the mainline Linux kernel this calendar year. The Kdbus support in systemd is disabled by default until the merging takes place since the API and ABI might still break as well.
Besides adding the initial Kdbus code for the kernel D-Bus, systemd 209 is "a massive new release, it includes a lot of new code. You probably don't want to base your LTS release on this. We hope to return to a shorter release cycle now to stabilize the new code. Expect a couple of bugfix releases over the next weeks," according to Poettering.
Systemd 209 has a new systemd-networkd component for configuring and bringing up your network, a systemd-socket-proxyd component as a bi-directional proxy for TCP sockets, support to save/restore rfkill and keyboard backlight states, udev improvements, new APIs, and tons of other improvements. Systemd 209 is one of the biggest releases I've seen in a while.
Those wanting to pour through the incredibly large number of changes for this release can find all the systemd 209 details via the systemd-devel mailing list.
There's no Fedora Rawhide packages yet since the systemd Fedora ARM package isn't building due to lack of IFUNC support, so Lennart is just contemplating on disabling systemd Fedora ARM support as the workaround... Meanwhile, GCC developers advise against depending upon IFUNC. GCC developer Jakub Jelinek wrote in the bug report, "requiring ifunc in systemd is way too premature, most architectures don't implement ifunc and that is hardly going to change any time soon. You can surely use it if available, but requiring it? Eh."