As a demographic, our lives differ from men's in subtle and surprising ways. Our motivations for getting on the web and our needs in general are different. You can find a lot of data online about these kinds of things.
I find it hard to generalize based on the people I know, who aren't typical of either gender. I hang out with geeks of both genders and tend to ask people what they think according their areas of expertise or the relationship I have with them.
More than anything else, I observed that more importance was given to aesthetics in general by women.
Does this small sample space scale? Can you share your experience?
she: I like this one.
me: the one with the orange background?!!
she: yes, it looks nice.
me: well...it's colorful; but for everyday use, you'd prefer the blue shade of course.
she: no, I like the orange.
me: are you serious?
she: yes.
me: you would want to see this page every day?!!!
she: yes.
me: hmmmmm
That's when I realized that it's important to add theme customization.
If you go to his website and look for Art of the Start presentations, you will see this as a major point.