But then how will I be able to watch the first half of season 3? Is it out on DVD already?

"The Swamp" was totally a filler episode. "Avatar Day" more than made up for it though. And yes, that's the last episode I've seen. I agree with you about the Fire Girl trio adding a much needed dimension to the story, although I wonder if Azula will get wearying. Zuko is a nice complex antagonist, so I hope Azula has some of the same layers.

Also, is it just me, or should lightning be a special case of air rather than of fire?