According to The Dominion Post, Jackson has had the rights to the award-winning post-apocalyptic novels. There are five books so far (the sixth will be released in April 2010) in the series, set in a world where cities have become massive moving entities that most devour one another in order to survive.
Jackson's publicist deferred to the writer/director/occasional genius, who was unavailable for comment. If this all pans out, it should be very interesting to see what Jackson and his Weta Workshop can do with some good 'ol steampunk. Personally, I have not yet seen The Lovely Bones, but just looking at the cover image for Mortal Engines, this seems like the sort of thing the Weta people could really sink their teeth into.
(via The Dominion Post)