The cover art suggests a fiery ending to Jane. I think Jane will summon the Phoenix and take it up on its original offer. She hands over Mjolnir to the Phoenix, in exchange for the Phoenix defeating Mangog. The God Tempest is revealed to be a being similar to the Phoenix, perhaps even a related-being or companion, which is finally released from Mjolnir's imprisonment.
Not bad. Not bad at all.
It does raise the question of why the phoenix would need jane to surrender mjolnir to it, but that ship has sailed.