this is just a theory:

I was thinking of the implicationns of galactus becoming butcher of worlds, the power inflation should put at the level of being fully or well fed, with power no one in the future timeline should be able to stop him from eating more planets and getting stronger...

this lleads to Necro G destroying the universe. Old thor feeling responsible for this, leads the attack on Necro G, this leads to the death of basically all gods and heroes from the future timeline leading to the end of the universe, with his two younger granddaughters dead, a dieing king thor sends frigg to the past to try to change the future, he sends her to the moon because mjolnir will be there...

she appears in the current timeline and feels moljinir calling to her on the moon, she picks it up and is transformed and decides to call herself Thor in honour of her grandfather who has gone soulsearching in the current timeline.

what do you guys think, would the new still be annoying if it was done similarly, do you think its frigg... i dont them calling her thor, but i have faith in Jason Aaron.

I think you are late to the party:

http://www.comicvine.com/thor/4005-2268/forums/who-is-the-new-female-thor-aka-marvel-publicity-st-1595225/#48

http://www.comicvine.com/thor/4005-2268/forums/could-frigg-take-thors-mantle-1584161/#37

hmm, hadnt seen those, any way i czan convert into a comment in one of those?