Yeah, this is just about the epidemy of all teasers. Grrr, come on December. Anyway, although the impending possible Zutara-ness of the next ep will make me entirely thrilled, I'm not thinking that I want his scar to go away. It makes him.. .Zuko. Without the scar, he's back to being a prince and out of his father's control though, so I guess the scar symbolizes more than anything else. I'm not quite sure which I'd like, though I will say that if the scar is healed, poor Iroh will have a heart attack. At least that's my guess.
and as to how they get into a tunnel together, think of the last scene of the Earth King. I can think of possibilities without using spoilers.
and again.... COME ON DECEMBER