Single-Sex Classrooms

I was meandering through the New York Times website and found an article on single-sex classrooms in an intermediate school. It goes on for quite a while about the research supporting single-sex classes, and while I understand it, I also wonder if they have looked at the social issues that occur when males and females finally do get to mix. Do girls feel more confident speaking out in class now that they have gained confidence in their all-female class, or do they still get intimidated by boys? I do understand that the male and female brains do work in very different ways (just read the first section about how the rooms are kept for each sex and the coloring ideas), but each person's brain also works very differently. We have yet to see a separation of classes into kinesthetic, visual, and aural learners. We still keep all of them together, so why not keep males and females together. Yes, they are both awkward during puberty; that will happen no matter what, but part of that is what makes middle school/junior high memorable.