eMarketer reports that digital music use rose from 16% of the US population (over the age of 12) in 2007 to 21% in 2008. That's about 12 million people who previously didn't use digital music who now do.
The full report is here:
http://www.emarketer.com/Article.aspx?id=1006360&src=article1_newsltr
I read a similar report that noted that the rapid growth of downloads didn't make up for the decline in packaged-media sales.
Probably not, but the Genie's not going back in the bottle, and I'd argue that that affects the whole audio business (which seems to be hell bent on imagining that there must be a way to get the Genie back in there).