I sort of asked this on another post and i asked Phil about this a while back, but, correct me if I'm wrong, the actual url the streamed video itself is on is "hidden" but if that can be obtained it should be recordable using rtmpdump/flvsrtreamer.
The only software I've come across that may have that ability are 2 windows applications, url sniffer and url snooper,
there may be way more to it than simply playing the stream with flvstreamer i.e encryption etc but if itv ever get round to making anything worth recording
it could be worth the effort, albeit on an idividual basis and not integrated into get_iplayerAny windows users out there tried either url sniffer or snooper ? if so does it work ? maybe poining toward channel 4 might be more fruitful than itv
in terms of content