I like Moiraine, but I'm forced to believe that she died when Lanfear and her fell through the Twisted Doorway. Fact 1: Moiraine told Lan that she had arranged for his Bond to be passed to another when she died. Fact 2: Soon after Moiraine disappeared through the Twisted Doorway Lan stated to Rand that he felt his new Aes Sedai somewhere far away. These two facts lend to the belief that Moiraine actually died. Though we know that it's possible for a Bond to be passed while the Aes Sedai is alive. It's also possible for Moiraine to have rigged it to appear that she died. Though I'm not sure what purpose this would serve, it would obviously have it's advantages. Either theory is plausible, but I think that the first is probably the correct one.