Mark Sinclair Vincent, aka Vin Diesel will both produce and star in a new MGM action/comedy titled The Machine, penned by the writers of Night at the Museum, and another action/comedy titled The Pacifier, which Da Diesel also starred in by the way. So there's already a relationship there it would appear.
In The Machine, Da Diesel will play "a human-like machine created in secrecy by the Pentagon to be the world's first ultimate weapon. Some 20 years after the machine was decommissioned and buried, The Machine is discovered, reactivated and befriended by a kid. When the government learns that The Machine is back in operation, the ultimate weapon's mission becomes to protect the family that is harboring him."
So, it's essentially like a live-action version of The Iron Giant - the 1999 animated film that also co-starred Win Diesel, who, by the way, provided the voice for the large robot. He provided the voice for a machine, now he's going to play one :)
There's no director attached to the project yet, although MGM reportedly is aiming for a fall start date.