Avatar: Legend of Korra Greenlit!
"Nickelodeon said in a release that “The Legend of Korra takes place 70 years after the events of ‘Avatar: The Last Airbender’ and follows the adventures of the Avatar after Aang - a passionate, rebellious, and fearless teenaged girl from the Southern Water Tribe named Korra.”
Korra’s quest eventually leads her to Republic City-the epicenter of the world of “Avatar.” A metropolis powered by steampunk-type technology, the city is inhabited by people from all nations. Korra finds that Republic City suffers from rampant crime and is also dealing with an anti-bender revolt. Korra is tutored by Aang’s son, Tenzin, is the ways of airbending."
Female Avatar protagonist? Can I get a hell yeah?
Also, they apparently have more than one Airbender, according to one young VA's twitter account I read a while back.
http://blogs.wsj.com/speakeasy/2010/07/21/avatar-the-last-airbender-nickelodeon-greenlights-tv-sequel-the-legend-of-korra/
And an interview here, includes stuff on the setting, how they decided to make Korra a girl etc.
It's interesting. :)
http://blogs.wsj.com/speakeasy/2010/07/21/legend-of-korra-the-creators-of-avatar-the-last-airbender-on-the-new-spinoff/