I found this website when I was reading about the new Illinois Early Learning and Development Standards. It is from George Washington University in Washington D.C. and it has a really nice and concise description of why we have early learning standards for children, birth through age 8.
If you scroll down you will find links to several sites and articles relevant to understanding early learning standards. It provides a bit of historical background about the national movement towards standards-based curriculum/education through NCLB. At the bottom of the page, there is a link to all of the state standards (if you are so inclined to take a look at what the other states are doing) and a list of references that might clarify all of this further. Take a look.