I was one of the many people whose response to Bob Dylan winning the Nobel prize for literature was "are you kidding me?!". There were plenty of people commenting on twitter that the Nobel committee were just trolling Philip Roth (or Leonard Cohen): all other men.
The Slate Double X Gabfest had an interesting discussion about whether the Nobel prizes are sexist, and went on to talk a bit about Dylan himself, and the myth of male "genius".
There have been rumours for years about Dylan being a contender for the Nobel - conveniently, the Nobel committees will never confirm or deny any names under consideration, which helps the traffic in this kind of speculation (along with all those supposedly "nominated for the Nobel Peace Prize").
But Dylan has acolytes, or rather, scholars of his genius in a way that women songwriters (and writers in general, in fact), tend not to. Female songwriters have fans, but not "ologists", scrutinising their work with Talmudic intensity, and writing dense scholarly narratives about their significance.
The great female songwriters of the last fifty years are never mentioned as Nobel contenders. The prizes can't be given posthumously, so Nina Simone is out of the running, as deserving as she would have been. Dolly Parton? Surely at least as great as Dylan. Carole King? At least she got a Broadway musical about her life (but then, so did Eva Peron).
I'm sure that the Nobel prizes are not consciously sexist, but they are part of a society that doesn't see in women a flash of the transcendent inspiration we attribute to "genius". After all, a woman writes a novel about marriage, it's called "chick lit" - when a Jonathan (Franzen or Foer) does the same thing, it's taken seriously as literature.
We can't disabuse society of the notion of male genius, but perhaps we can work on seeing women as geniuses too. Dolly Parton-ology: I'm going to make this a field.