Details are scarce, but what sets this new take apart is that it will be an origin story for Aramis, Porthos and Athos. As their backgrounds were shrouded in mystery, this means it will not really be using much that is actually written by Alexander Dumas.
The film is intended to be a franchise, with D'Artagnan appearing in the second or third installment.

The Musketeers are the latest established characters to be gathered under Millennium banner. The studio also has plans to revive Conan the Barbarian, Red Sonja, Hercules, and Buck Rogers, and is also responsible for the return of Rambo.