Stuart Townsend has left Sony's movie "Thor". Will it be any good?

Apparently 11 days before filming begins on Kenneth Branagh's "Thor" movie, Stuart Townsend has walked out. I find this hard to believe given that he was traumatised over Pater Jacksons' sudden re-casting of the role of Aragorn days before Townsend was due to play him on the big screen. What do you think really happened and will the movie be worth watching?