The project is being set up at Universal with a script from Chris Morgan, who has been earning the studio hand over fist lately with his scripts for the last two Fast & Furious movies as well as Wanted. Currently the immortal Keanu Reeves is the only actor attached to the project, meaning he's most likely to command the presumably effects-heavy film, something Reeves hasn't really done since 2005's Constantine. It's unclear precisely who he'll be playing in the story, but The Hollywood Reporter explains the script "centers on a group of 18th century samurai who set out to avenge the death of their master."
Aside from the above, details are rather vague, as always, in these early stages, but in my experience, samurai make everything better, so news on 47 Ronin is worth keeping an eye out for on their focal inclusion alone. Plus, it's nice to see Rinsch have a firm project to be attached to. You may not recognize his name, but you've probably seen a few of his commercials. His most visible job was probably creating the robotic Heineken keg commercial, but his most impressive is a brilliant Evolution of Technology spot. Check them both out below (plus another of his); and believe me, you'll want to see the Evolution of Tech one, it's a stunner.