I do agree, it's likely that at least some of the cast are still with us. My money is on Zuko, but my greatest hope is for Toph -- how awesome would Toph be as an old lady?

What I'm also looking forward to is the dichotomy of spiritualism vs. materialism, which would be incorporated with traditionalism vs. modernism.

Yeah, it will be interesting to see how that plays out. Also the idea of benders as an overclass, and the "underclass" non-benders whipping up a revolution. Although clearly the masked man has his own agenda, which may or may not involve anything to do with equality.