Anyone remember the part when Aang was falling and katara rose up on the wave to save him...well it reminded me of a painting of some sort of goddess or nymph but i cant remember it right now...anyway, they both were riding on the crest of a wave with their hair flowing behind and their arms arms back behind them...kinda like the figureheads on some old ships...but I though this might be a clue to the relationship between aang and katara based on which goddess/nymph is depicted this way. And also when aang was clearing the celestial chakra at the end and was shot, the giant representation of himself fell down too whereas when he voluntarily stopped it from happening with the guru, only he fell...so this prob means something which i'm guessing is the end of the avatar line but then again, i don't think nick would do that.
so based on the similarities between the eastern philosophies of chakra and the elements in avatar and naruto, here's something from the recent mangas on wiki "Yamato decides to explain elemental strengths and weaknesses to Naruto. After much dumbing down, he illustrates that each element is both stronger and weaker than another. The order is fire, wind, lightning, earth, and water, which each being weaker than the previous and stronger than the next. Water loops back into fire."
so this can help explain katara besting azula for a short time and then aang's(wind) eventual beating of azula(lightning)
so thats a few of my thoughts