That was the research stage - and the expect update in Jan 2010 did not happen. I was in discussion with Alan O at that time - and you can see replies from me to other blog posts that he made. But I do not think I ever saw a published URL or schema.
The reason for me bring it up on this post was because of the comment in the blog from John S that not all aggregators provide access to all 57 stations (should that be "varieties" ;) ). The implication that I drew from that is that there might be something missing from BBC - a parsable directory. If there is one then then next thing that could be missing is a published URL (that hobbyists can access as well).