Do they have such little creativity that they best they can do is make a female Thor?
Marvel Comics lost its creativity many years ago, probably no later than the time that the first Spider-Man movie debuted in the theaters (though I'd say a good 5-7 years prior). Ever since then, they 'shuffle the deck chairs' around, but nothing ever sticks. The characters always eventually revert to status quo. They make much, much more money from their licensing than they ever will on the comics, and they really don't want to kill that golden goose. Thor will be back as his usual self by the time Avengers 2 hits theaters. Bank on it.