Looks like this one might be happening in the next few years:
Jeff Wadlow to Write and Likely Direct X-Force
Just hours after we first posted news of a potential X-Force feature film, series creator Rob Liefeld confirmed that such a project was in development. Now, The Hollywood Reporter brings word that it's Kick-*** 2 helmer Jeff Wadlow who's attached to provide the screenplay for the project and is frontrunner to direct as well.
Described as the "militant" and "more aggresive" counter part to the X-Men, X-Force was first launched in the early '90s by Liefeld and Fabian Nicieza. The original team consisted of many fan favorite characters including Cable, Cannonball, Domino, Warpath, and Deadpool, but later incarnations have featured Wolverine, Psylocke, Sunspot, and Colossus.