I was wondering about this too. My best damage throwing (knives) has been a crit for 60pt. Usually it is 18-36 with lots of crits. As far as damage goes that's pretty weak compared to dual-weilding melee damage (even forgetting about proc damage).
Having said that, I am trying to max out throwing. Basic technique is to stand behind, /autofire summoned daggers, and rush in and backstab when it refreshes. DPS suffers but if you can get away with it, your throwing skill improves.
Anyone have info on better damage throwing items? Cannot really afford to /autofire some of the new javelins but I am curious. If you can get 200pt damage from throwing stuff, might be worth it.