My take is that with the events that happen when jane is brought from earth Odin holds her responsible for the invasion of asgard and in his traumatic loss.
Refusing help and forbiding Thor to make an attempt at rescue of jane Thor is forced to disobey Odin and free loki which leads to the final battle,Thor dealing with Kurse and Loki fighting Malekith...My take on the trailer scene with Thor, Jane and Loki is after the battle Loki is clearly hurt in his encounter with Malekith and Thor is holding Jane as they head back to asgard..Thor will have to deal with Odin and make a choice between asgard or earth.....
That sounds interesting actually. Especially the part that Thor sneakes to Loki's cell and will aks for help. Cause I doubt this was officially ordered by Odin. This has been in the comics numerous times... That Thor has to decide for one world. I can picture that beeing part of the story.
But why do you think Odin will make Jane responsible for the invasion of Asgard?