I don't see anything in the features document so I am wondering if any of the newer versions have incorporated the functionality for managing US taxes, incorporating the www.taxcloud.net API, for example?
the plugin has been available for ages
http://forum.virtuemart.net/index.php?topic=113564.msg381938#msg381938
https://www.google.be/search?q=virtuemart+taxcloud
http://extensions.joomla.org/extensions/extension-specific/virtuemart-extensions/virtuemart-orders/27175