I think that Olver is Gaidal Cain, although my evidence has little to do with that put forward by Ashram. Remeber when Birgitte was pulled from Tel'aran'rhiod? Around that time, she was moaning about Gaidal Cain not being anywhere in Tel'aran'rhiod that she could find - she theorised that he had been reborn, and that her time to be reborn was coming soon. And then, after being ripped from Tel'aran'rhiod, she was upset because Gaidal Cain always got himself into trouble - and she HAD to be there to save him from that trouble.
And then of course, we know that both Gaidal and Olver are incredibly ugly, which although isn't substantial in itself, just adds to the evidence. Birgitte also mentioned that time runs differently in Tel'aran'rhiod - although Gaidal was only missing from the World of Dreams for a short time, it's possibly that that amount of time was sufficient for him to be reborn, and to be several years old...
But then there is the issue of what purpose the Wheel would have for spinning out Gaidal, when he is only going to be a child for the events in this round of the War of Power - but then, the Wheel Weaves as the Wheel Wills....
wotmania says: The problem with the sequence of events is not necessarily how long Birgitte was missing Olver, but more that Olver is about seven years old (from what we know) and the battle at Falme was definitely not seven years ago (at least not in WoT time!). But of course there is that quote from Thom about the dead taking over the bodies of the living... I do not know for sure that Olver is Gaidal Cain, but it sure would be a fun plot twist!
Hmm......