@jaeezzy;
from monitoring lshal, here's what a connect and disconnect looks like -

08:06:04.813: computer_logicaldev_input_1 added
08:06:23.737: computer_logicaldev_input_1 removed

and there is no change in the headphone/state file - it's always disconnected, so assume that's for the wired headset only.

I ran a diff of lshal and the only bits that change when connected and disconnected is this line;

udi = '/org/freedesktop/Hal/devices/computer_logicaldev_input_1'
udi = '/org/freedesktop/Hal/devices/computer_logicaldev_input_0'

First is connected, second is disconnected - so a simple sanity check for input_1 would suffice for NOT enabling the loudspeaker when the keyboard is slid open.