So, as of a few weeks ago, it's no longer legal for libraries in those three states to lend out books (or other copyrighted material) produced outside of the US, unless they get approval of the rights-holder. It's also no longer legal for used-book stores in those states to sell such books without approval.
Along with this comes a worrisome possibility: US publishers might start moving their printing operations to facilities outside of the US specifically to block the resale and lending of the books. Judge J. Garvan Murtha, in his dissent on the court's ruling, noted that it was possible that this ruling...
would provide greater copyright protection to copies manufactured abroad than those manufactured domestically: Once a domestic copy has been sold, no matter where the sale occurred, the copyright holder's right to control its distribution is exhausted. I do not believe Congress intended to provide an incentive for U.S. copyright holders to manufacture copies of their work abroad.