Originally Posted by Rock Sexton
Thinking waaaaaaaay too much.
The first Thor movie already firmly established the line of succession for Asgard, and Thor is the only rightful heir. They're not going to introduce an extraneous (at this point) character like Balder into the movie as someone who moves ahead of Thor in that line; nor does a usurper make sense, given that speech. Again, there's only one God of Thunder.