I applaud the insane goal of the project and will probably try to help out. And certainly love my books for the reasons he suggests, but I disagree with the thesis that "there's always a role for books." It's like saying that there's always a role for album art (while people buy MP3s) or floppy disks.
They can be a kind of art that's impossible with more modern media, and the medium may have forced certain artistic decisions, but that's not necessarily a relevant role, and it ignores the fact that the majority of books are merely carriers for the content. Like, I own a mass-market paperback of "The Tempest." I doubt that anybody is more attached to that artifact than they are to the file (with pretty much the same text) hosted by Project Gutenberg.
But as I said, it's a great project. If nothing else, it'll be a good source to scan from as copyrights expire and an interesting kind of museum.