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.