Marvel Comics is making Thor a woman. From Time Magazine:
TIME: How do you think this will impact fans who have been with the male version of Thor for such a long time?
Jason Aaron, writer of the Thor series: If you’re a long-time Thor fan you know there’s kind of a tradition from time to time of somebody else picking up that hammer. Beta Ray Bill was a horse-faced alien guy who picked up the hammer. At one point Thor was a frog. So I think if we can accept Thor as a frog and a horse-faced alien, we should be able to accept a woman being able to pick up that hammer and wield it for a while, which surprisingly we’ve never really seen before.
Time: Marvel Comics Writers Explain Why They’re Making Thor a Woman