Chaos Space Marines also lost their best anit-air weapon (Doombolt used to auto-hit even fliers, but now it can't target them anymore). Dark Eldar have their anti-air weapons mounted on their own fliers though. And there's always the Aegis Defense Line if you really need a ground-air gun.
There's a lot of voices in the webway saying that Dark Eldar shouldn't have a Lord of War, because big equals slow and that just isn't our thing. I don't agree with them, but I see where they are comming from.