Just an FYI: there was a long and contentious thread a few years ago concerning the idea that women tend to have longer legs and shorter torsos than men. Someone finally linked to a page where Georgena Terry, probably the most experienced designer of women's bikes in the world, noted that the idea that women have longer legs than men is inaccurate: on average, in addition to being shorter than men, women tend to have proportionally shorter legs.

As I recall, Terry says that the need for specific bike designs for women stems, first, from the fact that standard bike frames designed around 27" and 700c wheels generally require some compromises to accommodate shorter riders, and, second, from the differences in the distribution of muscle mass between the two sexes.