Q: In this same Age, in a different Turning of the Wheel of Time, could it be possible that it wouldn't be Rand's soul that was spun out as the Dragon, but for a different, female soul to take on this role?
Jordan said "Yes" then maybe a few more words and only then did I remember to actually put the recorder on again...
RJ: ...it would have to be. Err, in the differences between the same Age in different turnings of the Wheel, are that.. as for an analogy: imagine two tapestries hanging on a wall, and you look at them from the back of the room to the front of the store. And to look at them, they look identical to you. But as you get closer, you begin to see differences. And if you get close enough, they don't look anything at all alike. That is the difference between the Ages. Between the Age in one Turning and the Age in another. So it's quite possible that someone other than Rand could be the reborn soul of the Dragon Reborn.
Q: It would be the same soul, or it would be a different soul?
RJ: It would be the same soul. That is, that is the belief of the world that I've set up, that it's the same soul. It's a soul of someone bound to the Wheel, which is spun out for the purposes, for the Wheel's purposes really, to attempt to re-balance the Weaving of the Pattern. But the soul would always be male. Souls don't change gender, so ... ...so the soul of the Dragon Reborn is always going to be male, just as Birgitte's soul is always born as a woman , just as Ameresu's soul...is always born as a woman. There are divisions here, and they are not interchangeable.

Plus:
Question from Jonan: Mr. Jordan, is it possible that in another Age, another Turning of the Wheel, that saidar could be tainted instead of saidin? This relates to the Female Dragon Theory.

Robert Jordan: That is not something I intend to explore.

Finally:
Female Dragon..NO when a female Hero is needed she is one of the ones bound to the Wheel. Jordan did mention a name but I didn't hear it. But he did say the Dragon is never female.

Let's try and clear some of this up... I can't remember the exact question, but from what I read in this thread, it doesn't matter (I haven't read the Female Dragon thread). RJ said that, no, it is not possible to have a female Dragon. If the Wheel needs a female Dragon, then it would weave in *insert female dragon name here*. Probably because of the blank faces he was getting he then added, you can find her in the scene where Mat blows the Horn...
He also said that a soul ready to be reborn cannot change gender, therefore the Dragon is ALWAYS male.