Digital is forever, or is it?

So today I was getting excited about scanning some family photos. The idea of having them on the computer and online equals access to them forever. However, it suddenly hit me is this what they thought when the photograph first arrived in the 1800's? Because now days a picture is no longer enough. It must be scanned archived and digitized since so much can happen to it in his hard form. Such as fires, water damage, torn or lost. We seem to think that just because we scanned it, we will have it forever. But the question is will we? What will our children and our children's, children do with photographs and how will they be stored say 100 years from now? Just got me wondering.