Are we heading for a digital obsolescense era?

In a short time our files that were digitalized will not be able to be opened.
If everything is digitalized and the power grid shuts down, then what?
No access to that stored info anymore.
Shouldn’t we keep hard copies as a backup?
There is a recent book on that very subject, but I cannot rember its title?
Does anyone know about it?
What good is Cloud IF we cannot access it?
I located an old website that talks of obsolete digital info.
http://en.wikipedia.org/wiki/Digital_obsolescence