I think that it is rather A-historical to ask if Shakespeare was a feminist. Feminism wasn't a twinkle in it's mother's eye in Shakespeare's day. One might call him a pre-Victorian romantic. He certainly believed than women were as intelligent as men (and some women more intelligent than some men - i.e. Romeo and Juliet or Portia and anyone else in that play).
In Shakespeare's day did women have anywhere near the rights and freedoms that Shakespeare gives his heroines? Shakespeare's women may be victims of a culture that treats them poorly, but the strong ones don't let that hold them back. Shakespeare highlights the unfairness of the system that women are in. Just listen to Beatrice or Portia. This is a step forward from the idea of women as subservient and happy with it or punished when they're not.
To Jacqueline Rose and Paula Berggren I ask: Is Shakespeare misandris for portraying so many of his male characters as brutes?
Don't go back in time and pick a fight with William Shakespeare. He isn't here to fight back and he's four hundred years behind on current social and political philosophy.
P.S. Think of the popular female heroines of the modern era and compare them with Shakespeare's women. Do you think Bella Swan could hold her own in a debate with Juliet Capulet?