According to Microsoft, a “digital feature project” based on the Halo game series is in fact in the works from 343 Industries, Xbox Entertainment Studios, and Ridley Scott’s Scott Free Productions. The feature will be released later this year and will be executive produced by Scott and Scott Free TV President David Zucker. Sergio Mimica-Gezzan (Battlestar Galactica, Heroes) will direct the feature.
http://ca.ign.com/articles/2014/04/03/ridley-scott-and-microsoft-team-for-halo-digital-feature
So this will be in addition to the Speilberg project. Could be interesting.