Let me get this out of the way right at the start - there is no island.
Now that we're clear on that, let me explain the premise of The Island. After the supposed contamination of the planet, the rescued survivors are being held in an underground facility where they are made to wear white clothes and eat healthily. Via daily lottery, one of their number is sent to "The Island" - a beautiful island, untouched by the contamination. It doesn't take long for Ewan McGregor to get suspicious and suspect that something strange is going on. Soon he discovers that there is no contamination, there is no island and he's not even a real person - he's the organ insurance policy of a wealthy playboy.
Although McGregor is aces with an American accent, I much prefer him with his native accent. Although he's one of the few foreign actors these days that can realistically play American - Christian Bale and Hugh Jackman are the other two - he still sounds better in Scottish.
Scarlett Johansson didn't do much in The Island, except stare at McGregor with those confused hound dog eyes - it just wasn't a very good role. The rest of the cast was decent. Steve Buscemi makes every film better and the film lost much of my interest the moment his character died. Also worth mentioning were Neelix and the guy from the Dairy Queen commercials.
There's not much original about The Island. It comes off as a mish-mash of Logan's Run and The Matrix, with a little bit of Brave New World thrown in, but the truth seems to be that The Island has little to do with those movies. It turns out that Dreamworks and Warner Bros are being sued by the makers of Parts: The Clonus Horror, on the grounds of copyright infringement. The Island is almost a shot for shot remake. Did Michael Bay just think that no one would notice? Parts was featured in an episode of MST3K - how could he not expect the nerds of the world to unite and overpower him? I hope he loses his ass in court.