Here is some Robert De Niro casting news that does not involve 50 Cent: The actor has signed on to reunite with Diane Keaton in Gently Down the Stream (directed by Justin Zackham, who scripted The Bucket List), where they’ll play a long-divorced couple who reluctantly pretend to still be married at their son’s wedding. Katherine Heigl and Amanda Seyfried will also star, so if you wanted to look at it this way, it’s as though Robert De Niro and Diane Keaton agreed to join a Katherine Heigl wedding comedy. That’s if you wanted to, though. Your decision. [Variety]