I like this quote from an interview with Lonely Planet's Gus Balbontin:
The essence of what the print people have known for 500 years is still the same in the digital world: you still have to publish great content. Yes, the tone may change a little. Yes, the experience might be slightly different. But at the end of the day, the people creating the content are humans. The people consuming it are also humans. The same humans that consume print consume digital. It's not different... In terms of the next 10 or 20 years, the essence of what publishers are doing won't change at all. This is what should make publishers feel comfortable about the future. The reason why you're there and the problems that you can solve for customers won't change.
I'm not sure 'comfortable' is the right word. But he makes an important point and one that's easily forgotten.