Heavily amended since it was first introduced, the bill now specifies that teachers in public school science classes will have to teach from state approved science textbooks. However, it also allows local teachers and school boards to introduce "supplemental materials" in science classes. The bill specifically mentions evolution, global warming and human cloning as topics on which such materials might be introduced.
Louisiana's Board of Elementary and Secondary Education would be able to prohibit the use of such materials if they are deemed inappropriate, under an amendment added in the House.
As of late, there seems to be a link between teaching about global warming (anthropogenic) and teaching about evolution, as if both are examples of scientists who have got it wrong and need top be straightened out. If the creationists are smart, they will push this because there is enough doubt in the minds of many people about global warming models. Interestingly, Josh Rosenau at Thoughts from Kansas has thought of this as well. As far as what the ACLU will do, the article notes:
Esman was asked Thursday if the ACLU might file suit against the Nevers measure once it becomes law or wait to see if religious materials are introduced into classes as a result of the law. "We're not going to say now what we may or may not do. That's a legal strategy," said Esman.