If you consider some of the characters who are ripe for dying in AMoL I think that you will agree with me that Perrin's death would be the biggest tragedy.

Everyone else will have performed a role that has suited their character, a role that they were meant to perform. Rand will have (presumably) sealed off the Dark One again. Matt* will have been the general commanding the forces of light. Lan will have personally rode into battle defending against the blight. Nynaeve has played a role in healing so much, from the healing being stiled to the madness brought on by the taint. Egwene united the Aes Sedai and destroyed a huge part of the Black Ajah. Moiraine found Rand and saved his life on many occasions.

But if you consider Perrin, he is the character in the series who does not belong. Perrin is very fond of telling us that he does not want to be hero-worshiped, he does not want to go to war, he does not want to live in the era that he is living. Perrin's fondest memories are of a time that took place mostly off-screen, ruling the Two Rivers, a time that was too boring to bother the reader about.

In my opinion, Perrin is meant for the world after. He is the re-builder. A role that he has played in The Two Rivers first as a blacksmith and then as a lord after the trollocs destroyed many homes. I am looking forward to him being a re-builder on a much larger scale.

This same argument can be made for Elayne and Aviendha if you wish but I'm replying to a Perrin thread so I'll leave it at this.

*I am aware of the outrigger novels that Robert Jordan had planned and Matt's role in them. I sometimes like to pretend that I never heard this huge spoiler.