In a likely preview of the Oscars, James Cameron (“Avatar”) will be going up against former spouse Katherine Bigelow (“The Hurt Locker”) when the Directors Guild of America hands out its awards on Jan. 30. Also nominated are Jason Reitman (“Up in the Air”), Quentin Tarantino (“Inglourious Basterds”) and Lee Daniels (“Precious”). The DGA awards are considered the most highly predictive of the pre-Oscar awards, with the winner going on to win the Best Director Academy Award with very few exceptions. More often that not, the Best Director winner’s picture goes on to win the Oscar, though there have been more split decisions over the last decade. It’s not hard at all to imagine a scenario where Cameron wins an Oscar as a producer of “Avatar” while Bigelow becomes the very first woman to win a Best Director Oscar. First, the former couple will be going head to head for the directing trophy at the Golden Globes on Jan. 17.