The Pennsylvania Academic Standards require students to learn about Darwin's Theory of Evolution and eventually to take a standardized test of which evolution is a part.
Because Darwin's Theory is a theory, it continues to be tested as new evidence is discovered. The theory is not a fact. Gaps in the theory exist for which there is no evidence. A theory is defined as a well-tested explanation that unifies a braod range of observations.
Intelligent Design is an explanation of the origins of life that differs from Darwin's view. The reference book, Of Pandas and People, is available for students who might be interested in gaining an understanding of what intelligent design actually involves.
With respect to any theory, students are encouraged to keep an open mind. The school leaves the discussion of the Origins of Life to individuals students and their families. As a Standards-driven district, class instruction focuses upon preparing students to achieve proficiency on Standards-based assessments.
A District Federal Judge in the US has ruled that this curiously-capitalised attempt to sneak in a mention of intelligent design, the viewpoint that opposes Darwinism by claiming that only the existence of a supreme being can account for the variety of life on earth, into the teaching of science in public schools violates the Constitution, in particular the "no establishment" clause of the first ammendment. Intelligent design, like creationism before it, has thus been found to have no place within a secular science curriculum, despite both Bush and Blair suggesting to the contrary.
The debate on this issue has been, and remains, fairly heated; and we can be sure that this most recent development will be greeted with outpourings of both delight and disgust, in equally spectacular terms: see, for example, Brian Leiter's post on this topic, entitled "Federal Judge hands the Pennsylvania Taliban a Stinging defeat" (although it does seem true that the judge himself pulled no punches in his criticism of the school board from Dover, Pennsylvania).
What is clear is that it is a zero tolerance approach that has been adopted by this decision. The school board's policy may have appeared innocuous enough - requiring teachers to read out the brief, four paragraph passage before proceeding to teach Darwinism, which, in itself, seems to have relatively little objectionable about it. The passage stated that Darwinism is "only" a theory in which gaps exist, mention intelligent design as an alternative, and suggest some further reading for those interested. The judge decided, however, that this was a thinly-veiled attempt to reintroduce religion into the science classroom, thus borrowing for the former some of the prestige accorded to the latter. He did not belittle the bona fides of the beliefs of those proposing it (although he did suggest that they had been less than honest about their motives for doing so), but rather insisted that the "theory" had no scientific basis at all, certainly not enough to justify inclusion of even a mention of it in a class about Darwinism.
Anyway, an important case, even for those of us who know little or less about the actual substance of the science involved; more detail on it here, here, here and here.
Oh, and for anyone a little confused by my title, see here and here. I can only expect that this decision will hold also in this regard...