This is something that totally flew under my radar until recently, so forgive me for being a week late. Not long ago at this years Comic-Con in San Diego, M. Night Shyamalan made an appearance (via Satellite) at the Avatar: The Last Airbender panel. Although it was really brief and short on the details, it does show that Night is serious about this film and that he looks to start production as soon as he wraps on The Happening.
[See the video for yourself]