One of my favorite Silverlight developers (who is working on our Rough Cut Editor project )  Ezequiel Jadib who works at SouthWorks in Buenos Aires posted an awesome article on how to start, stop, and shutdown smooth streaming publishing points. 

He did a great job of digging through the API in Reflector and figuring things out quickly.

http://blogs.southworks.net/ejadib/2009/04/16/live-smooth-streaming-how-to-start-stop-shutdown-a-publishing-point-programmatically/

The nice part about this is that we had a scenario on one of our test servers where we wanted to constantly loop a video on a publishing point so that it appeared to be a Live stream (since in these economic times we were too cheap to set up a live encoder).  So E-Z (I call him that because he makes my life easy) used the tools in the Smooth Stream SDK to play back a 10 minute clip and restart the publishing point infinitely.