Brief Summary
The Set-Up
It's the beginning of the end of the Second Wave of Feminism. (Don't worry: there'll be a sequel called the Third Wave.) The social reforms that have been accomplished in the name of equal rights are impressive, but not enough. So when Le Guin is asked to be the commencement speaker at the graduation of a well-known women's college, she has some things to say about what it means to be a woman.
The Text
Le Guin wants to make it abundantly clear that now is the time for women to claim their own place in American society. They need to stop fighting for success as it's defined in a man's world, and instead get more comfortable with what it means to succeed as a woman in a woman's world.
She advocates separatism, to a certain degree, in order to establish places where women can be women without the patriarchal framework upon which American society was built, so that they can finally achieve their own level of greatness.
Plus, you know, the future lies with women. (Men would have an awfully hard time trying to procreate on their own…)
TL;DR
Le Guin says women rule…so let's stop letting men boss us around.