I have found some pretty interesting software for displaying AIS information on a chart. Has anyone ever heard of TV32 (a.k.a TransView 32) from the Volpe Center?
So far it looks like it can display AIS information as well as GPS, and Gyro information from IP network or com ports. Puts your boat on the chart from the GPS input and shows all the AIS contacts around you. You can also set it up to monitor your boat and to alert you if you go outside an area for anchor dragging or what have you. I don't really think it would be all that suitable for navigation but I really don't know much about it.