If you haven't seen Seven Samurai do so immediately. It is one of my favorite movies, and I consider it a "perfect movie", a movie that I can find no fault in whatsoever. But that's not surprising considering Kurosawa's perfectionism.
I don't see the point in remaking this movie unless they are going in some completely new direction (sci-fi/fantasy perhaps?). I consider this on the same level as remaking Citizen Kane or Casablanca. There is no reason for it.

I can understand remaking a flawed or unknown movie. Ocean's Eleven is an example of a so-so movie getting made into something much better. The Departed is an example of a good foreign film getting made into an equally good (perhaps superior) movie for a different culture. Those remakes both work very successfully.
I Am Legend was probably ripe for a remake. Unfortunately it's also an example of a remake that gets it more wrong than the original. Although I Am Legend shares its title with its source material, it is actually much farther removed from the original story than the seventies film version, The Omega Man. It's a completely missed opportunity. (Also, the special effects sucked, but that's a completely different topic.)
I just can't picture a Samurai remake that could improve on the original in any way. Especially since the cast is going to contain American and European stars, in addition to Asian. Hwuh? Whatever.