also Id look into archival DVD's. As far as I know they should be on the market in a few months. THis also applies to cdr's (apparently the US army backed up 30years of medical records to cdrs only to find out they were unreadable after a couple of years). Now they are suing the supplier.
THere is no guarantee with cdrs they may last a few months or a few years, as it has to do with evaporation of the coating. (CDrs that are actually pressed will not have that problem) There are archival cdrs available (I just got some to back up family photos etc). They are a bit more pricey - but still only around $2 (Canadian) a piece. They are guaranteed for 300 years.

I am finding that some of the dvds I made of my baby daughter only last year or so, are unreadable on the dvd player, so Im looking forward to getting archival dvds.