Will Smith is the main antagonist in the US version of Oldboy?
I think i just threw up in my mouth.
Anyhow, i think its the nature of the story. The elaborate scheme to torture the man that "killed' a mans sister of whom which he loved (and not as just a sister) and "got pregnant". To go through all that just to make someone else life miserable, even at the expense of his own life, takes alot of rage and dedication. Not to mention, what he DID to that person, is beyond fucked up.
Steven Spielberg mentioned that he was interested in making a US version of Oldboy and that he wanted it to star Will Smith. However, he also said that it will actually not be a remake of the Korean film but, rather, be based on the original Japanese manga. And, if you don't know, the manga doesn't have the infamous twist ending like the movie. So, in short, the US version of Oldboy will be a lot different.
On a side note:
Did you know that Bollywood already remade (read: "ripped off") Oldboy. There was a movie entitled "Zinda" that came out a few years ago, which was a nearly shot-for-shot rip-off of Oldboy. But, of course, some of the plot details were changed and, again, the twist was removed. Bollywood can't handle that sort of twist.