This is a fantastic idea, and I love seeing libraries stretch in the services that they provide.
However, I do have to add my "books are not dead" disclaimer to this. The problem with discourse about libraries by non librarians is that, for the most part, people really don't understand how many types of libraries there are (beyond public libraries), and the kinds of (book related) services they provide beyond being holding tanks for all those best-seller beach reads.
First, there is this assumption that some day every book ever published is going to be available in a digital format - and, if Google Books and Project Gutenberg have it their way, most likely will be. It does not, however, necessarily follow that those digital files will be equally accessible. Anyone who has kept up with or tried to use Google Books should know that, while a fantastic service, it has limitations - particularly, copyright limitations. Many libraries are also riding this trend by adding digital holdings to their collection - which, again, great! I'm all about variety - I'm not anti-digital, I just don't think it's the Holy Grail.
First, this is a socioeconomic issue (and, this one does apply primarily to public libraries). The kinds of people who want libraries to go digital are the kinds of people who can afford fancy gadgets on which to read digital books. A large percentage of public library patrons can't. Part of the reason that I become so dismayed when public libraries face budget cuts in times of recession is that, for many of their patrons, the library is their sole point of connection to the world. A lot of the services that libraries provide are directed toward those who are already economically vulnerable. They may not even have a phone line at home, let alone a personal computer or internet connection. Increasingly, the library serves as a community center and cyber-cafe (and, as anyone who has worked in a public library well knows, the computer-oriented regulars are some of its most enthusiastic patrons). Many of these people are searching for jobs, and their only point of contact is their e-mail address... and their only way to access their e-mail is at the library. And, while some of these people come to the library solely to use a computer, a lot of them check out books as well. What happens to them in the event of a digital switch? Yes, they could come to the library and read digital books on the 1 or 2 hours a day that they're allowed to come to use a public computer - but, as established above, a lot of them have real work to be doing on the computer during that time.
Reading is a leisure pursuit. Granted, it's a valuable and enriching leisure pursuit , but without time for leisure, one doesn't really get to do it. So, in the case of those patrons who don't have access to the technology needed to read e-books at their leisure, their access to information (or, even, those best-selling beach reads for recreation and pleasure) would be restricted, de facto. Along with budget cuts come cuts in library hours. And there are only so many computers, and there is only so long you can let someone use them when there's a line of other people waiting for their turn. And, yes, technology is becoming cheaper and more accessible, but, there will always be a class of people for whom it remains beyond their means. So, what about them?
Beyond this, and beyond my usual I-just-prefer-real-books rant, I see this everything-worth-knowing-or-reading-will-someday-be-digital-so-screw-real-books attitude as unrealistic, particularly when it comes to archives and non-public libraries. I have no real statistics for this, but it is my guess that there are probably more private, archival, academic, and non-public libraries than there are public libraries. These are libraries with fragile, or highly specialized collections. These are often small libraries without the means to digitize their collections. These are often libraries with the sole existing copy of a particular book in the world, and it's falling apart, and trying to scan it would be its death sentence. These are libraries with public documents, and non-published ephemera. A lot of this stuff is making it in to online databases, don't get me wrong, however, even having these things available digitally does not lessen the archival importance of the physical materials. In a lot of these articles, "book storage facility" (or some variation thereof) is said like its a dirty word. Like the only important thing about books is what they have written in them. In these minds, the book, itself, has no prima facie value, so once it's online... I don't know, burn it? Even if they ever did become completely redundant, what WOULD we do with all of these books anyway? Fill dumps with them? Pave roads with them? Mind you, I think that there probably are too many books being published (but, that's a matter of quantity over quality, and the subject of an entirely different rant regarding my problems with the publishing industry). I'd like to see a "greener" solution. But, the fact remains, there are still a whole lot of books out there, and we do need somewhere to put them.