Are Old Books Becoming Irrelevant?

I wonder if the day is fast approaching when old books as unique sources of information will be functionally obsolete? From Cornell's Making of America to the University of Michigan digitizing program and now this story about a similar project at the University of North Carolina, it seems that older titles everywhere are going online. From my own experience, I can say that for my next book, I examined dozens of obscure titles online via Google Book Search, Live Search, and other databases rather than having to go through the lengthy and sometimes unfruitful ILL process. Could the day come when the public's primary interest in old books will be as historical artifacts rather than as sources of data?