Based on what I seen in the premire, I doubt Lillith is dead. The vampire Bible states she met the True Deat by meeting the sun. But when Bill drunk her blood and got all of her abilities he was able to walk in the sun, a stake in the heart couldn't kill him, nor did the fire. Based on the preview he may have walked in Sookies house without permission. It seems she doesnt share the same weaknesses that the other vampires do. So could she really be dead?, hopefully those images Bill saw might shed some light on the matter. Lillith could have been banished to another dimension like what the faerie elder tried to do with Russel and she left her blood behind so that one day a vampire could save her, who knows.