The usual creationist suspects are babbling in the comments to my article on textbook stickers, and throwing aside the usual empty apologetics and assertions that they are promoting secular atheism and weird claims about Jefferson and bizarre ideas that Einstein 'proved' Newton wrong, the only interesting argument is that scientists ought not to be distressed at a declaration that our knowledge is provisional and subject to revision, and that students should keep an open mind. The answer is that we aren't distressed at all by that; in fact, our textbooks already say it over and over, and typically have long chapters that introduce the scientific method and describe how it works and what its limitations are.
For instance, Campbell's Biology, fourth edition, has an extensive section on the hypothetico-deductive method, and comes right out and says it explicitly:
Even the most thoroughly tested hypotheses are accepted only conditionally, pending further investigation.
Scott Freeman's Biological Science, second edition, also describes several key theories in some depth, and explains what makes them useful:
This chapter has introduced some of the great ideas in biology. The development of the cell theory and the theory of evolution by natural selection provided cornerstones when the science was young; the tree of life is a relatively recent insight that has revolutionized the way researchers understand the diversity of life on Earth.
These theories are considered great because they explain fundamental aspects of nature, and because they have consistently been shown to be correct. They are considered correct because they have withstood extensive testing. How do biologists test ideas about the way the natural world work? The answer is that they test the predictions made by alternative hypotheses, often by setting up carefully designed experiments.
Then follows several examples of hypothesis testing, one a test of why giraffes have long necks (no, not the Lamarckian idea…but whether it is a result of food competition or sexual competition) and another about the adaptive value of capsaicin in chili peppers. The examples are accompanied by discussion of key concepts like controls, the null hypothesis, repetition, etc.
Life, seventh edition, by Purves et al. also has a general section that discusses the hypothesis-prediction approach to doing science, illustrated with the examples of two hypotheses to explain frog extinctions, the role of UV-B and airborne pesticides. They make this summary statement:
Scientific methods are the most powerful tools that humans have developed to understand how the world works. Their strength is founded on the development of hypotheses that can be tested. The process is self-correcting because if the evidence fails to support a hypothesis, it is either abandoned or modified and subjected to further tests. In addition, because scientists publish detailed descriptions of the methods they use to test hypotheses, other scientists can—and often do—repeat those experiments. Therefore, any error or dishonesty usually is discovered. That is why, in contrast to politicians, scientists around the world usually trust one another's results.
If you understand the methods of science, you can distinguish science from non-science. Art, music, literature, activities that contribute massively to the quality of human life, are not science. They help us understand what it means to live in a complex world. Religion is not science, either. Religious beliefs give us meaning and spiritual guidance, and they form the basis for establishing values. Scientific information helps create the context in which values are discussed and established, but cannot tell us what those values should be.
That's far too charitable to religion for my taste, but it does illustrate a general attitude you'll find in the books: they tend to distance themselves from religious issues (quite appropriately, I think), do not promote any kind of atheism, do not proclaim science infallible, and quite the contrary to what creationists like to imply, are damned quick to explain that science is not above criticism and in fact thrives on testing alternative explanations.
The objections to the textbook sticker approach is that 1) at best, they are redundant, echoing what the book already says, 2) they are narrow, selectively targeting evolution while ignoring all other theories, and thereby giving the false impression that evolution is particularly weak, and 3) they tend to promote weak hypotheses, like Intelligent Design or vague "religious theories", as equivalent to strongly supported theories like evolution. If you actually read the introductory chapters to these textbooks, you'll discover that Intelligent Design creationism fails to meet the criteria for a legitimate scientific hypothesis, lacking observations in support and failing to make any predictions that can be tested.
That says that school boards must be in a sorry state, when it's obvious from their scribblings that the people who write these textbook stickers haven't even bothered to read the first chapter of the books they want to label.