We have couple of casting bits to bring you this Friday afternoon. First up, Robin Williams has joined writer/director Justin Zackham's (writer, The Bucket List) wedding comedy Gently Down the Stream. Williams brings another star to an already stellar cast that includes Robert De Niro, Diane Keaton, Amanda Seyfried, and Katherine Heigl. Per Variety, the Oscar-winning actor will play the role of Father Monaghan in the pic that tells the story of a long-divorced couple (De Niro and Keaton) who pretend that they're still married for the sake of their adopted son's upcoming wedding. Rounding out the Gently Down the Stream cast are Susan Sarandon, Patricia Rae, and Ben Barnes. Production on the film is expected to begin this July.Speaking of Ben Barnes, The Chronicles of Narnia actor has signed on to star alongside Jeff Bridges and Julianne Moore in the Warner Bros./Legendary Pictures fantasy project The Seventh Son. Variety reports that Barnes is in line for the title role (the same one Sam Claffin was once in talks for) which is described as "the seventh son of a seventh son" who learns all things wizard-related. Directed by Sergei Bodrov (Mongol: The Rise of Genghis Khan), the pic is based on Joseph Delaney's young adult book series. For more on the project, hit the jump to read a synopsis for the series' first installment, Revenge of the Witch.the-last-apprentice-revenge-of-the-witch-book-coverHere's the synopsis for Joseph Delaney's Revenge of the Witch [from Amazon]:

For years, Old Gregory has been the Spook for the county, ridding the local villages of evil. Now his time is coming to an end. But who will take over for him? Twenty-nine apprentices have tried–some floundered, some fled, some failed to stay alive.

Only Thomas Ward is left. He’s the last hope; the last apprentice.

Can Thomas succeed? Will he learn the difference between a benign witch and a malevolent one? Does the Spook’s warning against girls with pointy shoes include Alice? And what will happen if Thomas accidentally frees Mother Malkin, the most evil witch in the county…?