The problem with translating Metroid into a movie is that, like most videogames, Metroid is great by video game standards but fairly generic by movie standards.
Though, if done right, it could still make for a cool movie.....if John Woo isn't involved.
"A Metroid movie would be very hard to get right, but if they DID get it right it could revolutionise movies! No talking, no narration, only one character, yet still exciting! It would need to be VERY good though, but it's possible!"
I think 2001 came pretty close to that. ...and, you, know, 2001 is exactly what this thing needs to be like: moody, artisitic, visually stunning, little dialogue, etc.
Of course, what we're likely to get is a Paul WS Anderson-style cheezy, frantically paced, action movie. Oh well.