Luggage is luggage and so long as you do not sign any waivers it should be covered by the same liability limits that apply to everything else. I think the waiver on the back of the tag they make you sign limits their liability in case of damage but not loss but I am not sure about that.

For what it's worth, I have shipped LCD panels and PCs in their original packaging as luggage several times and never experienced any worse than the usual luggage delays.