Microsoft and Showtime are still working on developing a live-action television series based on the Halo game franchise. The show was first announced back in May 2013 with the reveal of the Xbox One console, with Steven Spielberg as one of its executive producers. Showtime's involvement was first reported in May 2014.
Since then, most of Microsoft's plans to offer non-gaming TV and film content exclusively on the Xbox One were cancelled with the elimination of the company's Xbox Entertainment Studios, but the Halo TV series survived the purge. IGN reports that during the Television Critics Association press tour, Showtime president David Nevins was asked about the status of the Halo series and if the network was still involved:
"Nevins had a very quick answer, but one that did seem to indicate there continues to be a very good chance of seeing the series down the line, as he simply answered, "It's still in development. Still in very active development." I asked Nevins if we could hear any more details soon, and he replied, with a laugh, "No time soon."
In the meantime, Microsoft will release a three-part CGI animated series, Halo: The Fall of Reach, as part of the launch for the Xbox One game Halo 5: Guardians on October 27.
Source: IGN