According to http://www.nasa.gov/centers/wallops/missions/tacsat3.html, the May 8 launch of Tacsat 3 and the other 3 payloads was scrubbed until later in May. Will update as soon as a new date is announced.
Original story at http://mt-milcom.blogspot.com/2009/05/rocket-set-for-launch-on-virginia.html