I was listening to the audio of The Great Hunt today, and I something Ba'alzamon said to Rand made me wonder if the Wheel is so much of a circle that Ishamael/Moridin is the same person as the Dragon but a cycle ahead, twisted and tainted by evil to serve the Dark One. It's in Chapter 15 where Ba'alzamon is talking about how some people fight each other so long and know each other so well that when they strike at one another it's as if the vitcim guides the blow to his own body. Then the taunting about wanting Rand to see his face, almost as if he knows that Rand will recognize himself behind the mask. There's probably tons of evidence to dispute this, but it seemed like an interesting thought when I had it.