According to a post on his message board, Amazing Spider-Man/Thor writer J. Michael Straczynski is working on a screenplay for a “big budget historical movie” based on the life of King David. He also gives an update on his comic projects in the same post:
I’m three issues into Thor, four issues into the secret project I’m writing for Marvel, Spider-Ham comes out shortly (couldn’t love it more), Bullet Points 2 comes out this week, and in general I’m keeping busy.
Note: Image above is from Kyle Baker’s King David Vertigo project; as far as I know, it has nothing to do with JMS’s project beyond the similar subject matter. It’s also worth checking out if you haven’t read it.