Zuko is still alive and well in ‘The Legend of Korra’ according to the interactive Republic City on Nick.com. He stepped down as Fire Lord Years ago and now travels the world as an ambassador for peace.
Zuko gave the thrown to his daughter, who hopefully still carries the same peaceful mentality as her father.
Because Zuko was kept alive, I feel that we’ll see him at some point during an episode of ‘The Legend of Korra’. But he’ll be different: He will be very old, and he won’t have Dante Basco’s wispy voice. Bummer.