We say surprising in that Coppola hasn't traditionally focused on tales for younger audiences – her movies tend to delve deeper into adult issues, although last years The Bling Ring did focus on young people looking to achieve their dreams, so perhaps this is simply an extension of that.
Joe Wright (Anna Karenina) – who is busy building the new world of Peter Pan – had been down to direct, with Kelly Marcel (Saving Mr. Banks) and Abi Morgan (The Iron Lady) both producing drafts of the script. Now Caroline Thompson (no stranger to fairy tale stories herself with Edward Scissorhands and Corpse Bride on her resume) taking a crack at the story of the young mermaid who falls for a human prince. Will Coppola make it a darker vision than the Walt Disney animated feature? Given that the script derives from a children's theatre company version, we'd doubt it, but a lot can happen between the page and the screen.