No, he's not getting a sex change operation. Rather, as Whoopi Goldberg explained on "The View":
The character is one of Marvel's oldest superheroes. He was first introduced in 1962 by a team consisting of Stan Lee, Larry Lieber, and Jack Kirby, and was based on the god of Norse mythology. Thor was sent to Earth by his father, Odin, to learn humility. There, he fell in love with a human woman, Jane Foster, and became a member of the Avengers.
Not much else was revealed on "The View," but co-host Jenny McCarthy did tease that the new female Thor models herself after her male predecessor because he saved her life. And she is apparently Thor in every way, as Marvel Digital's executive editorial director explains:
Hey, Chris Hemsworth would make a pretty woman.
"This is not She-Thor. This is not Lady Thor. This is not Thorita. This is THOR." - @jasonaaron- Ryan Penagos (@AgentM) July 15, 2014
Photo courtesy Marvel