The Avatar (2009) director has been trying to get a new take on the miniaturisation science fiction adventure afloat as a producer for years now, burning through such name directors as Roland Emmerich (Independence Day), Shawn Levy (Real Steel) and, though he was only considering the job, Paul Greengrass (Captain Phillips). The project currently has a script by Justin Rhodes (Contract Killers) based on David Goyer's (The Dark Knight) treatment. According to The Hollywood Reporter, they would both stay on board to work with Guillermo del Toro if he does officially take the job.
Cameron has had dreams of a big blockbuster version of the story for ages, which in the 1966 original finds a team of scientists shrunk to atomic size and injected with a miniature submarine into the body of a scientist whose life is under threat. It certainly sounds like a fun project for del Toro to work on while the Pacific Rim (2013) sequels linger in development limbo.
We will have to wait and see if he signs on, especially given that he has plenty of other projects under consideration. As always, watch this space.