Having worked in IT for 25 years I can definitely say that while there are nations that are slowly eliminating the gender bias (often way too slowly), parts of the IT industry lag seriously behind. You only have to read this article by Wendy Schuchart to see we still have some way to go. I just hope the people who organize these sort of events are listening to people like Wendy, but I sadly doubt it. Of course EMC or VMware may blame their external partners, but it is not difficult to discourage this sort of behaviour.
Maybe it's time for some positive discrimination? IBM has a great track history here, way back to the early 30s. But while the sales part of the business appears to attract women and men in fairly even numbers, the more technical roles remain male dominated. I have never been certain why (though I have some ideas).
So if you are responsible in any way in organising IT industry events, please read Wendy's article and share it around. Consider it mandatory reading:
Of course there are worse industries out there. Just look at auto industry trade shows.