IMDB currently lists the film as being in pre-production and has Bill Nighy and Helena Bonham Carter attached to star. The synopsis is short, but states, " hitman tries to retire but a beautiful thief may change his plans." No word yet on what Rupert's role may be!
Further digging around has revealed that the film will begin shooting this month and locations will include London and the Isle of Man. Wild Target is also being labeled as a comedy/drama (dramady, if you will!), and is based off of a 1993 French film called "Cible Emouvante".
Good news is this also seems to be a big budget film, and should see a fairly wide release! One site has even gone so far as to mention a March 2009 release date, but please note this purely speculation at this point since filming has not even begun.
UPDATE: A filmography page for Wild Target is now up! It features a better synopsis regarding the original French film, and leads us to believe that Rupert's role will be that of the apprentice to Bill Nighy's hitman!
Story developing, and we can't wait to learn more about this new film!
UPDATE #2: A more detailed synopsis of the film has been released. It confirms that Rupert will be playing Antoine, the apprentice of hitman Victor played by Bill Nighy:
"This dark comedy has a middle-aged hitman Victor Meynard (played by Bill Nighy) go on his last hit job before he retires. He ends up running into a delivery boy, Antoine (Rupert Grint). Unable to kill the adolescent, Meynard adopts him as his apprentice, in spite of Antoine's evident lack of enthusiasm for his new career. They are hired by a Corsican gangster to kill a con artist RenÃ©e Dandrieux (Helena Bonham Carter). Again, Meynard's luck is against him, and when he fails to kill RenÃ©e, with Antoine's help, the Corsican gangster sends another hitman to kill all three of them."
The filming will begin on September 16.