Divergent accessibility standards

Are federal and state governments on different tracks when it comes to implementing web accessibility standards? On his Vox Populus blog, Mark Headd notes that federal law sets accessibility standards for federal agencies but it's not clear whether the rules also apply to state governments. New York, among other states, follows the W3C's Web Accessibility Initiative, which is similar but not the same as the federal standard. IBM's Frances West also notes a divergence between US and foreign standards, noting "If various governments mandate different regional or country technical requirements, industry will be forced to focus on multiple compliance efforts, rather than pushing beyond compliance and investing in new technology and solutions.” But Headd notes that divergence in the US could have the same negative impact. "If Section 508 does, in fact, apply to state governments in the US someone ought to tell them. If industry is saddled with having to engineer solutions to meet multiple sets of accessibility standards, it could mean time taken away from work on new solutions to make web content and services more accessible.