The survivors and they're destiny:
1.Katara - She will became a powerful teacher who will help with the restoration of the water tribe.
2.Sokka - He will became a powerful leader of his tribe.
3.Toph - I honestly don't have a clue.
4.Zuko - Became the Firelord, nothing to see here.
5.Ty Lee - Goes back to the circus.
6.Mai - Marry Zuko, be happy.
7.Azula - Her passion turn's into art, and art + lust for power leads to the way to dominate the world through brainwashing people with art. In short - she creates the first manga in the Avatar world.