http://r23.cc/interface/ is a very nice example of audio streaming with server-side Pd.
hum, there is an update on this, the new map component is there : http://gollum.artefacte.org/mapuse/map.html
the map itself is not pd, but some emitters ( radios ) use pd patches to link this to a netjuke database that enables to make playlist and programation.
so, r23 itself uses pd, but the global infrastructure ( http://giss.tv ) allows to use any software to stream ( Muse, IceS, libshout, ... )
cheers, sevy