Well, like I said, PaperBack is really just for curiosity sake or experimentation - not a real backup solution. I don't really think that ink-jet printers with office grade paper is a good backup solution. However, I still believe that the considerations for long-term data archiving present an interesting, non-trivial problem.
But, if anyone's interested, I'll lay down $100 that my inkjet printout of whatever text document will still be usable in 50 years while your copy of that same document on a CD will be a useless hunk of plastic. Unfortunately, that $100 will only be good for a soda pop. Oh, and I'll likely be a useless pile of ashes, so maybe we should just hang on to our $100.