There has been a lot of speculation as to who Gaidal Cain has been reborn as in the Wheel of Time Universe. I haven't seen anyone else say this, so I wanted to get it out there first. I think that Gaidal Cain was reborn as Jur and Sora Grady's son Gadren. In Towers of Midnight, Grady tells Perrin (I think it was Perrin) that his young son is ugly, but he loves him still.
Gaidal Cain is Gadren Grady,
P.S. After a little more searching, I found some people had already postulated this. Oh well. RAFO