Masterpiece, Antique Road Show, American Masters, American Experience, This Old House, MotorWeek, NOVA, Nature, Frontline, Autsin City Limits. These all appear to use the same API. So, if PBS Kids was done, it appears these would work as well.
http://video.pbs.org/ lists the video collections.
Maybe someone can review the API and see if it's possible to create a plugin for PBS.
Thanks!
<edit> I do see there was a PBS
http://forum.serviio.org/viewtopic.php?f=20&t=4370 thread in the Available Plugins Forum, but there was no real resolution outside of "PBS is now somewhat in Hulu".