No joke, after leaving STAR WARS: ROGUE ONE and seeing the full-CG Gran Moff Tarkin, the first thought that came to my mind was: holy shit, now they can do GEMINI MAN! This is a film that's been in development for at least twenty years now (and one I've always been interested in), with everyone from Harrison Ford to Mel Gibson attached to the role. And the premise is pretty genius: "an aging assassin must battle a younger clone of himself, at the peak of his abilities". Sounds rad to me!
And it seems Ang Lee may be the one to bring this film to screen! At one point, Tony Scott and Joe Carnahan were attached to it, but honestly, Lee seems like a perfect fit. Lee is no stranger to pushing CG limits with films like LIFE OF PI and HULK (to differing degrees of success), and he's also proven himself adept with action, having directed CROUCHING TIGER, HIDDEN DRAGON.
I also feel the technology has made great leaps and bounds in the ensuing years (the project was always intended to have an older actor play against a de-aged CG version of himself, even in the late '90s when it first originated). And we've seen the technique used in TRON: LEGACY, the two latest TERMINATOR movies (both times the highlight of the films), the aforementioned ROGUE ONE, as well as CAPTAIN AMERICA: CIVIL WAR and ANT-MAN. Hell, even the upcoming PIRATES OF THE CARIBBEAN: DEAD MAN'S CHEST will have a de-aged Johnny Depp in it. And, compare the trailer for POTC: DMC with TRON: LEGACY, you'll see it's basically the difference between PS1 and real life. Not only that, but many people couldn't even tell that Tarkin was CG unless they knew in advance (creating, I'd argue, a confirmation bias).
But, regardless, this has the makings of an awesome action movie! So who would you want to see fight his younger self? Maybe Sylvester Stallone?