My speculation.
They are about to kiss, when suddenly stopped by a sudden arrival of Zuko and Iroh, Hiding from captors. Zuko will attack Aang, but Iroh will try to talk sense into him. since now no matter what he does, Zuko can never go back home. Zuko won't listen, get into a fight and lose. they will then tie him down and have a civilized conversation with Iroh. thus leading to a future alliance
Note: I made this up as I was typing. and I didn't stop typing since I started.
Edited on 03/17/2006 10:08pm