If you're wondering why there's been no casting announcements for Guillermo del Toro's upcoming Hobbit prequels, it's because Del Toro and his script partners Peter Jackson, Fran Walsh and Philippa Boyens are waiting for the script to be completed first. While promoting the release for the Hellboy II: The Golden Army DVD, the director updated Ryan Rotten on why they're waiting.
"Literally, like every week, what you discover writing the two movies, writing the two stories, it changes. So, every week there's a discovery, and anything we say this week would be contradicted next week. Certainly that would be true in casting. Why create hopes or why create expectations if down the line you're going to go, 'You know what? That was not a good idea.'"
While we have no casting announcements for The Hobbit: Part 1 and Part 2, nearly all the leading stars from Peter Jackson's Lord of the Rings trilogy have told numerous media outlets of their desire to return to the prequels. Since the second part of the planned duology plans to take the audience near the timeframe where Peter began within his trilogy, even Orland Bloom and Sean Astin are willing to return to their characters near the end if Del Toro and the writing team find a way to fit them into the overall story. Cate Blanchett and Hugo Weaving have also expressed a desire to return to their elven characters. So no casting confirmations will come for sometime but we know most of them will return if they're written into the scripts.