Problem: when did "slut" come to mean "a woman who is honest about her sex drive, and enjoys sex?" Because I never heard it used that way until the slut walk movement started up. Up until that point, I'd always understood it to mean "woman who sleeps around to an unsafe degree. Female equivalent of man-whore." Why are we supposed to act like that's a good thing again?
Edit: more specifically, it has connotations of using men for sex and casting them aside like old laundry. A woman who has sex with a lot of men isn't a slut. A woman who hits on random strangers with the express intent of getting something from them, whether the sex itself or something in return for sex, and who -- importantly -- doesn't give a rip about the feelings of her targets, would in fact be a slut. I kind of feel like "woman who enjoys sex" is an attempt to re-define it as something positive, not the actual traditional definition of the word.