I'm going to venture a guess... Jane won't die and will retain Mjolnir, while Thor himself will pick up some new form of weapon (weapons?) that will have abilities similar to Mjolnir.
I feel we'll be stuck with Jane so long as Aaron is at the helm. I don't understand the hype around him.
I could be wrong but I read that Jane will be dying or losing the power of Thor at the end of this current arc. Then Aaron's new run with the fresh start begins and the Odinson is back as the God of Thunder. I personally am really looking forward to the book. I hate what was done to characters like Thor and Hulk over the last few years but I think this Fresh start marks both of their returns.