I’ve also got this same issue after updating. This is on a friend’s computer who is halfway across the country, so I’ve been doing a lot of remote troubleshooting. What I’ve got so far:
If you edit the boot options and add a " 3" to the end of “linux” boot line you’ll be able to at least get a console. From there, you can fix the networking with netctl reenable <interface>
Unfortunately, I’ve still had no luck getting dbus running.
systemctl start dbus.service
Dec 09 23:47:56 remote-host systemd[1]: dbus.service: Main process exited, code=exited, status=1/FAILURE
Dec 09 23:47:56 remote-host systemd[1]: dbus.service: Failed with result 'exit-code'.
Dec 09 23:47:56 remote-host systemd[1]: Started D-Bus System Message Bus.
Dec 09 23:47:56 remote-host dbus-daemon[1962]: Failed to start message bus: Failed to drop capabilities: Success
Dec 09 23:47:56 remote-host systemd[1]: dbus.service: Main process exited, code=exited, status=1/FAILURE
Dec 09 23:47:56 remote-host systemd[1]: dbus.service: Failed with result 'exit-code'.
Dec 09 23:47:56 remote-host systemd[1]: Started D-Bus System Message Bus.
Dec 09 23:47:56 remote-host dbus-daemon[1964]: Failed to start message bus: Failed to drop capabilities: Success
Dec 09 23:47:56 remote-host systemd[1]: dbus.service: Main process exited, code=exited, status=1/FAILURE
Dec 09 23:47:56 remote-host systemd[1]: dbus.service: Failed with result 'exit-code'.
Dec 09 23:47:56 remote-host systemd[1]: Started D-Bus System Message Bus.
Dec 09 23:47:56 remote-host dbus-daemon[1966]: Failed to start message bus: Failed to drop capabilities: Success
Dec 09 23:47:56 remote-host systemd[1]: dbus.service: Main process exited, code=exited, status=1/FAILURE
Dec 09 23:47:56 remote-host systemd[1]: dbus.service: Failed with result 'exit-code'.
Dec 09 23:47:56 remote-host systemd[1]: Started D-Bus System Message Bus.
Dec 09 23:47:56 remote-host dbus-daemon[1968]: Failed to start message bus: Failed to drop capabilities: Success
Dec 09 23:47:56 remote-host systemd[1]: dbus.service: Main process exited, code=exited, status=1/FAILURE
Dec 09 23:47:56 remote-host systemd[1]: dbus.service: Failed with result 'exit-code'.
Dec 09 23:47:56 remote-host systemd[1]: dbus.service: Start request repeated too quickly.
Dec 09 23:47:56 remote-host systemd[1]: dbus.service: Failed with result 'exit-code'.
Dec 09 23:47:56 remote-host systemd[1]: Failed to start D-Bus System Message Bus.
Pretty sure this is at the root of everything else failing.