I think I remember this being discussed before on this list, but I
couldn't find it in the archives. I apologize in advance if...

I installed alpha4 on my AspireOne over the weekend. I got suspend
working as a user with tweaks to polkit, and it shows up as an option in
the XFCE Power Manager dialog. I told it to suspend when closing the
lid.

I also proved that acpi knows when the lid is closed using this script:

#!/bin/sh

cat /proc/acpi/button/lid/LID/state # state: open
echo "Close lid now"
sleep 2
cat /proc/acpi/button/lid/LID/state # state: closed

systemd is not installed:

dpkg -l | grep systemd

ii  libsystemd0:amd64
215-17+deb8u3                        amd64        systemd utility
library
ii  systemd-shim                                                9-1
amd64        shim for systemd

I suspect some systemd vestige is causing this.