Just found an article on the BBC site that is of interest - 'Rosetta stone' offers digital lifeline. Some nice pointers to research on the life of CDs and DVDs with numbers to use at presentations and it is comforting to read that what we're trying to do Just Aint Easy(tm).
I rather like this too:
"...the digital data archivists' arch enemy: magnetic polarity"
(I added the bold!)
Does that make digital archivists like the X-Men ? ;-)