This is one conference where you have no need to dress up at all for normal day to day stuff. You may want something if you're going to a meeting or a nice dinner. Otherwise normal attire is jeans or shorts and t-shirts. Microsoft and speakers are usually the best dressed in khaki and polos.
This conference is male centric attendance wise. There are women, just a low ratio. I'd say there is a higher ratio of women in the speakers than attendees.