It appears the school is concerned with is bringing their test scores up to standard. Because of No Child Left Behind, struggling school districts are scrambling to implement courses of action to improve test scores so they don't face outside intervention.
I'm sure they're not trying to stop physical attraction between the sexes, but instead are trying to maximize learning potential by recognizing the differences in the way boys and girls learn and behave.
What if it works?
I think it is a great idea. I've been real tempted to try to send my son to an all boys school. He's very smart, but he needs school to be hands on and fast paced.
The co-ed schools pander to girls currently. They do not teach in a style that is good for boys. There is too much sitting, and not enough hands on activities.