Let us not forget that fundamentalist Christians already have succeeded at banning Harry Potter books in school libraries in more than a few states. As someone mentioned, it is usually the school classrooms and libraries most at risk.
For the record, I work in a public secondary inner city school library, and we have 5 versions of the Bible, but only one version of the Torah and the Qu'ran. Contemporary World Religions is a year long course taught in the school. Students have the right to organize a student group and meet in school (extracurricular) for the purpose of praying. Muslim students have a classroom set aside for them right now to pray during Ramadan.
The idea that public schools are religion free is pretty much an urban myth. However, the important thing to remember is that Christian religion is being taught as one of many religious mythologies worldwide, not as the one and only truth. Creationism and evolution debates are part of the curriculum--but not exclusively in science class. It is also taught in some parts of the social studies curriculum.
But each school is different. The schools in the area where CarolC had her problems is likely much more conservative.
Hope that clears things up for those who are wondering.