hopefully they keep the nostalgia factor down; sure, the characters of Airbender were awesome, but this series needs to stand on its own with its own characters and writing. I do worry about Korra knowing three elements off the bat and her personality written as "independent, fearless, and hot-headed" which, if not right, can turn into Mary-Suedom (or fanservice for people wishing Toph was the main character). Anyway, I am looking forward to this.

"It may be set 70 years in the future.
Aang is featured in the series in the Spirit World, as Roku and past Avatars were to Aang in the Last Airbender.
Korra is from the Southern Water Tribe.
She has already mastered three of the four elements prior to the series, and is trying to master "Air". Aang's son, Tenzin, is supposed to teach it to her.
Most of the story revolves around a steampunk metropolis called Republic City. It's the epicenter of the world, and a virtual melting pot but is plagued by crime and a growing anti-bending revolution that threatens to rip the city apart."

Edit: http://tv.ign.com/articles/110/1107556p1.html

The Only detail not confirmed is Aang in the Spirit world, but I'm certain he'll be apart of the series.