@Paul re What Content
Paul, I think you've misunderstood, afaict the AC in "What Content?" has hit the nail on the head. Not much of what you watch on the BBC these days is solely owned by the BBC ; your own post points out that if the BBC don't have sole rights, then the Beeb almost certainly need someone else's agreement (the other rights owner(s)) before the stuff can be redistributed.
You also mention the fact that many BBC programmes include copyrighted music. Dr Who fans will have enjoyed the Dr Who Confidential series, which wasn't on the DVDs, even though Dr Who is actually one of the few notable "BBC" programmes. Why not? Because of rights issues over the music in the programmes (some of which was contemporary chart type musak). Maybe someone should have foreseen that, but they didn't.
Even apparently classic BBC stuff like "Coast" isn't a BBC-owned production; the Open University have joint rights to that one.
The continued non-appearance of the BBC Creative Archive, announced by Greg Dyke back in 2003, highlights the fact that getting "BBC content" out there is a non trivial exercise even when there's no money changing hands to argue over and when most of the content in question predates the "independent production" era: http://news.bbc.co.uk/1/hi/entertainment/tv_and_radio/3177479.stm
And let's ignore the larger question in this picture: why people who can spell torrent will choose to pay for stuff they can already get at zero cost, and which they can get without any DRM infestation. Unless the pigopolists can get the ISPs to act as their enforcers, which hasn't worked so far.
 There may be lots of programmes which are "pure BBC", but how many big name productions are "pure BBC"? Not many.