The details are scarce (and it may not happen at all), so it's not known whether this would be a straight up-remake or a rewrite, or who Maguire or DiCaprio would be playing. But the idea is enough to undoubtedly cause reactions of anger and panic around film fans, but think about this calmly. It's not as though Maguire, DiCaprio, or Knight are untalented slouches, and it's the kind of story that could be given a modern rewrite and stand on its own feet. I would actually love to see this rewritten, and set in Iraq or Afghanistan. I'd love to see it set it in years immediately preceding the Soviet Union, putting Harry Lime and Holly Martins in the dangerous, free-for-all Yeltsin economy. (Faraci suggests making it sci-fi, which would be very brave and very awesome.)
The Third Man is one of those stories like Dashiell Hammet's Red Harvest that is flexible enough to work in another adaptation and lose nothing of its original power. I'm very curious to see if this comes together, and in what form. DiCaprio would be the perfect actor to play the smirking Lime. I just hope they don't mimic my favorite scene. Some things are better left to Welles.