Scripting the new Leopard System Image Utility in shell without Automator??

Does anyone have any information on how to script the functions of the SIU in the shell? I am trying to take the InstaDMG script on step further and have it not only create the images, but create the NetBoot/NetInstall sets auto-magically. I have been able to take the Automator actions that ship bundled with the Leopard Admin tools (SUI) and install them so they can be used in the standard Automator (Instead on only inside of SIU), but this is still not flexible enough Any thought would be helpful. Thanks Steve