There seems to be a fraction of women in high-end IT positions compared to the numbers studying the stuff. My class was about 60-40 men to women split, yet I've yet to meet a professional woman IT anything!.
My boss's daughter worked with me one summer, showed her some cool tricks in excel with VBA, and she was certainly smart enough to understand it all - she's studying for a degree in astro physics and her dad owns a MEMS/microchip company, hmmmmmm really can't see VBA coding as her choice of career.
Some people maintain that there's lots of women in the industry professionally, but not in programming, they're far more likely to be in artwork departments, texturing, modelling, sound, etc. I think mens brains are better geared for coding, as sexist as that sounds - remember men use the logic side of their brain more, and don't do crazy things like try to use both halves of our brain at once. No offence to all the 1337 coder-women here.
Aegrescit medendo