The GNOME developers announced a few days ago that the first development release of the upcoming GNOME Settings Daemon 3.12 package, a daemon run by all GNOME sessions to provide live access to configuration settings and the changes done to them, is available for download and testing.
Therefore, GNOME Settings Daemon has been updated to support the new UPower API, the org.gnome.SettingsDaemon.Power D-Bus interface has been removed, as it is now deprecated by the new UPower.
GNOME Settings Daemon 3.11.1 is now able to handle rfkill for WWAN modems, the battery recall support code has been removed, the brightness keys have been fixed for less than 20 brightness steps, and the plugin functionality has been merged into the XSettings plugin.
More details about this development release of the GNOME Settings Daemon package can be found in the official raw changelog.
Download GNOME Settings Daemon 3.11.1 right now from Softpedia. Remember that this is a development version and it should NOT be installed on production machines. It is intended for testing purposes only.