I would not put something I wanted to keep that long on "doggies little toy"
or "ate my momma".  You get the picture.  I do not think DLT and 8mm are
reliable enough to be comfortable that they will be able to be restored that
far out.  This is a nasty problem for all of us.  LTO is too new to bet on
and we are limited by what we can do.  In the mainframe world you archive
the stuff and just keep some tape drives around.  Open is different.  The
issue is the vendors have not stepped up to the fact that open has longterm
data now, just like a mainframe.