They aren't mutually exclusive either. For that matter, they don't exclude other theories; Rand could die, go to Tel'aran'rhiod, and then be brought back to Moridins body through the agency of Nynaeve, possibly informed and/or assisted by Elayne. But Rand in a new body has been foreshadowed too many times in too many ways for me to believe it's just a red herring Jordan threw out because he knew people would go fishing. The same can be said to a great degree about Nynaeve healing him, but, once again, the two aren't mutually exclusive, and the scenario I used to illustrate that is just one of many possible ones.

If I have to pick just one, I'll go with body swap if only because it seems like an open question how much longer Rand could survive in his current body even if Tarmon Gaidon never came, though it would also allow him the only shot at the return to obscurity he craves. It's hard to keep a low profile when there are pictures of you fighting the devil in the sky floating around an entire continent. Faking your own death is one thing; Rand needs a plastic surgeon, or a Mask of Mirrors that can survive a handshake.