I hope you don't mind if I'm not interested in spending a few hours tracking down all the sources I've referenced before but to give you a short answer to your first paragraph: for the past decade or so women have held 20-30% of the CS degrees with recent times being somewhat higher. Women also hold less than 20% of the software positions (http://www.pbs.org/newshour/rundown/2012/04/science-engineer... ctrl-F for "19 percent"; it cites the Bureau of Labor Statistics but I'm not sure what part). Obviously there's not a perfect correlation between degrees and jobs for a number of obvious reasons but it's evidence against equal chance of CS majors staying jobs. And I've seen separate sources more clearly showing that there is larger fall-off for women than men. Unfortunately, I don't know what the cause is exactly.
However, your second paragraph sort of has things backwards. The current scheme of things strongly signals to women (pretty accurately) "your odds of getting hired are lesser than your equally talented male friend." Such signalling as I described before isn't about saying that their odds are better than their male friend but rather that the company is actively trying to not disadvantage women.
The current scheme of things strongly signals to women (pretty accurately) "your odds of getting hired are lesser than your equally talented male friend."
Do you have some sort of evidence for this? Anecdotally, talented female programmers stay on the market far shorter than males do. Most companies desire a gender balance, which makes the limited stock of female programmers more vlauable.
However, your second paragraph sort of has things backwards. The current scheme of things strongly signals to women (pretty accurately) "your odds of getting hired are lesser than your equally talented male friend." Such signalling as I described before isn't about saying that their odds are better than their male friend but rather that the company is actively trying to not disadvantage women.