SF Signal recently asked several writers whether there are any taboos left in science fiction novels. A few said no, but many felt that lots of topics are too hot to touch.
Nancy Jane Moore said:
I wouldn't go so far as to suggest that a taboo exists against feminist material - or political material generally . . . But it does seem as if fiction that goes farther than simply writing a woman character into a role once reserved solely for male ones is not common in mass market fiction. It's nice to see the kick-ass heroines, but I am hungry for meatier material.
Check out the whole conversation at SF Signal.