City of Ember: the movie.

Looks like they're changing the plot pretty significantly:

Plot Synopsis: When the planet's atmosphere grows too toxic, Earth's citizens move to underground cities. Two teenagers dominate the story, one who longs to be a messenger because the job will allow her to venture above ground, while the other dreams of working underground to repair a generator whose failure will doom the city's power supply.

So... Who is Bill Murray going to play?  Will he wear a fat suit to be the mayor?  That could be fun.