You may read USDA's press release, with many more links, here. And to see the final rules, go here. The comments and response section of the CEP rule, beginning on pg. 9, may be of interest to schools participating or considering participation in the CEP.
N.b., the "snack foods" rule may mean changes to the items offered in vending machine at your school (if the school participates in the NSLP).