If anything was ever going to make up for the loss of the Hollywood-produced live action Halo film, it's 343 Industries's Forward Unto Dawn
that is being shown in five 20 minute parts, released weekly, on YouTube's Machinima Prime channel.
It's not a fan film, and it's better than your average SyFy original movie (and probably better than their surprisingly not awful Red Faction movie from last year). It's definitely worth checking out.
Be warned that some of the language is NSFW.