so... The air benders really were wiped out. I was clinging to the notion that there was a secret base somewhere, that some escaped and were in hiding. I didn't know at the time that the show would deal with themes as mature as outright genocide. Now I'm sad because if he's truly the last airbender that means that's it, after him it will be a lost art forever. Heck that would affect the cycle of avatars, it would probably end anyway.
And what did happen to Zuko's mother? We didn't get to hear what the former Fire Lord said.
And what is the fate of Azula? They didn't show. If anyone is likely to disturb the peace, break out of prison, start a coup de tat, and overthrow Zuko, it's her.