Very conveniently, for the last few months the Sky HD+ box has worked with an external HD connected to the eSATA port on the rear of the unit.
After a software update on the 20th August 2013 the eSATA port is once again inoperative.
It was reported in the Daily Telegraph today that BBC Radio 3 will be available as a 320kbps AAC stream from December.
This follows the very successful trial during the Proms
More BBC stations to follow in the new year evidently
And here is a link explaining, in a bit more technical depth, about the Proms experimental streams