nicu - 12:59 am on Jul 19, 2009 (gmt 0)

Assuming the disk is playable, 20 years from now there might not be any players available. You can't legally copy it in the U.S. because of the DMCA. The copyright is really irrelevant because you need to break the encryption to make a copy.

If I'm not mistaken, the courts have ruled time and time again that it's perfectly legal to make a personal backup copy of your media, to protect against damage to fragile media. This includes music CDs, software, etc. Of course, you may not distribute these backup copies, but that isn't the issue at hand. So that being the case, yes, your disk (or backup) should be playable for 20 years. Unless, of course, I'm missing something here.