Yeah it is, and here are some facts I have on the movie so far:
Shyamalan is directing the movie. Noah Ringer is playing Aang (his first role). Nicola Peltz is playing Katara. Dev Patel is playing Zuko. Jackson Rathbone is playing Sokka. For those who are worried, Michael Dante DiMartino (one of the creators) is helping with the writing. There have been several casting calls for extras in the Philadelphia area (I actually got to attend one

). They are shooting in Greenland this month, presumably for N. & S. water tribe scenes, and the two other filming locations I've heard were Philly (in classic Shyamalan fashion) and Vietnam.