Gears was the story of your usual rag-tag group of soldiers known as the Delta Squad. When the planet Sera (a stand-in for Earth) is attacked by an alien force called the Locust Horde, Delta Squad is forced to defend the planet from this unstoppable enemy. Most of the story focused on Marcus Fenix and the rest of the Delta Squad, so I would imagine that the film would take their cue from the game and do the same.
Previous talk surrounding the film had producers looking to make a green-screen extravaganza a la 300, and judging from what I have seen of the game, it looks like green screen is the only thing that could save the film from a runaway F/X budget. This time last year, Latino Review had gotten their hands on an early treatment for the film. Godfrey also confirmed that G.I. Joe scribe Stuart Beattie (along with Gears designer, Cliff Bleszinski) will be in charge of the script. Now that Godfrey has gotten chatty about the film, I would assume that we should start hearing word of casting soon (starting with a director), if they want to make that 2010 deadline.