This could get awkward

According to this report, Apple may be considering shutting down the iTunes store:

Apple could shut down iTunes, the world's biggest online music store, if a ruling expected tomorrow forces the company to pay more to music makers for each downloaded track.

The Copyright Royalty Board (CRB) in Washington DC will decide whether to grant the request of American music publishers to increase royalty rates on songs bought from online music stores such as iTunes.

The National Music Publishers' Association, which represents the interests of music makers and songwriters in the US, want rates to be increased 9 cents to 15 cents, which represents a 66 per cent rise.

Folks on the iPhone mailing list are recommending that anyone who has bought music from the iTunes store ensure that they have the files backed up, just in case. I can't imagine any mechanism that would allow Apple to rescind previous sales, no matter what the situation may be with future sales of media through the iTunes store.