That's right, the expansion plug-in for Escape Velocity has been release. Fall of the Voinian Empire picks up sometime after when the player achieves one of Override's Central Objectives.
For the moment, you can download the plug-in at this (url="http://"http://evula.org/ddstation/FOTVE1.0.0.sit")link(/url) until such time when the plug-in will be available on the addons page.