The source for the NetBoot/SUS Appliance has been made available on github. We are looking forward to seeing what the community has to offer in driving this forward. You will find minor fixes and updates to the appliance on github before we version to another OVA, so check it out if you want the latest and greatest.
You now can also do a text based auto install of the appliance on Ubuntu 10.04.x by specifying the following on the command line of the Ubuntu Server installer:
install auto=true priority=critical url=http://cloud.github.com/downloads/jamf/NetSUS/NetSUS-1.02.seed