My basic gripe with Bell-curve arguments against female genius is that at the high end, in the exponential tail, fine-tuning is needed to explain why a non-negligible fraction of professors at MIT (say) are women. Even a small difference in variance would lead to overwhelming male dominance.
On the other hand, if there were no difference in the distribution of intelligence, but cultural factors held women back, then the current "one-tenth to one-third" fraction of women in jobs needing high intelligence is naturally explained.
A recent PNAS paper showed that International Mathematics Olympiad teams from countries with high gender equality contain more women. http://www.pnas.org/content/106/22/8801.abstract
IMO team members are one-in-a-hundred-thousand people - deep into the exponential tail of any Bell curve.
A study in 1999 showed 70% of psychology professors hiring Robert, and 45% hiring Ruth, on the basis of an identical CV. The waters of geek sexism run deep.
Cordelia Fine wrote a good book on the evidence. PDF: http://hagocrat.files.wordpress.com/2012/06/delusions-of-gen...
It's totally anecdotal, but the young people in the canteen at JPL are about 50/50.
Notice also the political fine-tuning of the variance argument: it doesn't dare suggest that mean female intelligence is lower (because we'd all reject that). God of the gaps, anyone?
Getting this right matters. If you must hire very good people, and you have the wrong model of how very good people are distributed among the population, you will fail.