Well, here's what he's doing next...
I like the look of it, have always been interesting in Roman history and Noel Clarke is among the cast. (Mickey the Idiot, saving the Legionaries?)
Personally I think some of Marshall's most interesting film ideas are the ones he hasn't made yet including:
Outpost which he described as a story about zombies terrorizing an oil rig and The Sword and the Fury, a planned project about a heist that takes place in medieval times. The story takes place 30 years after the death of King Arthur when his sword Excalibur is stolen. Arthur's queen Guinevere hires a band of thieves to steal it back.
Let me know what you think to Centurion based on this trailer.