I always warn people to be wary of following trends because often by the time they do so, the trend is over. But there is one that you might want to heed, and that might help you sell projects you already have written, and that's the trend toward more family movies.
An article at SFGate.com, the site of the San Francisco Chronicle, points out that seven PG movies could end up ranking among the 20 highest-grossing films of the past year. And next year has even more such films lined up, including the next "Narnia" film ("Prince Caspian"), "Where the Wild Things Are," and "The Spiderwick Chronicles." Furthermore, some experts feel that this trend will extend to video games and online media as well.
If what you are writing is family-friendly, you may find the marketplace more friendly as well.