i updated my system to debian testing. hal is installed but it is deprecated now and is not started at boottime. the xfce4-power-manager depend on the hal deamon I think. After I log into xfce 4.8.0 i get a pop-up menu showing the message "hal deamon is not running"
version 0.8.x no longer supported, also HAL have been deprecated since 3 years already, please consider using a new version of xfpm.