I really like Peter Weir, so I'm interested. As for Ronan, I think it's just hard to say. Child prodigy actors have a habit of peaking early. Then they grow up and suddenly what seemed like enormous talent at a young age is totally mediocre in adulthood. See Haley Joel Osment, Mckuley (sp?) Kulkin, Sookie Stackhouse (drawing a blank on her real name, lol), Fred Savage (actually was he ever considered talented, or just cute?).
Maybe she'll carry it through and be great as an adult. Hopefully in the mean time she gets better roles than the retched Lovely Bones, though. The Hobbit has a pretty good chance. Though, unfortunately it's the same director as the Lovely Bones. He did a good job with Lord of the Rings, though it's way too sappy and has an extraordinarily obtrusive score. It's a tragedy that MGM's stupid bankruptcy drama ended up making Del Toro quit. He's a far better director.