Hi contracycle,
I think the effects of feminism on popular culture can be discerned from the ease with which "bitch" passed into widely-used acceptable slang: that is, pretty much nil.
First of all the impact of feminism isn't limited to culture. The idea that women should be allowed to have jobs, to vote, etc. now seems pretty mundane but this is a profound achievement of feminism only in the last century - so the impact in economic and political arenas are more impressive than the cultural.
In any case culture (in terms of rap music, TV shows, etc) is pretty much dominated by rich white guys anyway and its the easiest place for them to hit back against the real achievements of feminists. A lot of pop culture is completely fake (rich white capitalist men fear blacks and women, so they promote culture that makes blacks out to be criminals, and women as whores). Watch a movie by a feminist director from algeria or egypt and you will immediately realise that north american culture that is supposed to be culturally feminist, i.e. that show supposedly strong women - I mean sex and the city, etc. - watch a movie by one of these women directors from egypt or algeria and you'll see what a joke north american feminism becomes when it's incorporated into safe mainstream entertainment.
north american and much european "culture" (Tv industry, pop industry, fashion industry) is a whore in itself. notice that these are all cultural arenas that are operated by a very specialized elite, not "normal people". They're the industrial production of corporate culture. Why be surprised when this kind of culture is racist and sexist?
mick