I always find that quote a funny one, considering "Hell" wasn't fire and brimstone but ice and death's cold grip. Hell is supposed to be the farthest from God, yet why would it be fire when fire is a source of light and warmth when God is lord of? Always a funny quote to me.
Truly, I could see the writers throwing Zuko in with the Aang Gang, but could more easily not so. I'm waiting to see what the writers have in store for Zuko before I'll be able to make up my find.