After Peter Jackson left the project due to studio disputes, rumors have it that that Steven Spielberg is currently in active negotiations to oversee the Halo movie production.
According to film site IESB, "nameless studio executives" said that Spielberg was "blown away" by the screenplay written by Stuart Beattie, which is mostly based on Eric Nylunds first Halo novel, "Halo: The Fall of Reach." The novel is a prequel to the first Halo game, and it tells the story of how Master Chief became The Master Chief.
Spielberg didn't comment on the rumor, but Microsoft issued an official response stating that " We [Microsoft] are glad there's still a lot of enthusiasm in the entertainment industry surrounding the idea of a Halo movie. That said, the Halo feature film remains on hold as we focus on projects like Halo 3: ODST and Halo: Reach."