With Mako gone, I'm sure they had trouble getting the same feeling Iroh let off, even with Greg Baldwin. (In which he still did very well imo) I mentioned a while back that if they do a spin off, it might be about Iroh's past life. We don't know much about that at all.
Actually getting to see Lu Ten, see Iroh's wife and what happened to her, Iroh as a child with his brother Ozai and father Azulon, watch Iroh fight in the war and lead his men into battle at Ba Sing Se. That sounds very exciting and I would scream in glee as a schoolgirl would if that was the case.
Edit: I forgot to mention his trip to the spirit world and his encounter with the Sun Warriors and how it effected him. Also, Iroh's reaction to his father's mysterious death and his brother becoming FL before him. There's just so much to learn about Iroh still!
Edited on 04/23/2008 9:42am