I have never been as attracted to books as objects so much as for what they contain. Those who know me might raise their eyebrows at this--I have an awful lot of books. But I have rarely minded cheap editions or used ones; as long as a book was readable, I'd be happy enough to own it.
Of course, some books are attractive primarily because of their physical aspect: my Abrams art book on collage, with its tipped-in pictures and two-color letterpress printing; the book about the Peacock Room that I am reading now. And some books are really more convenient and useful in their analog state--like travel guidebooks and field guides, so you can flip through when you don't know what you're looking for.
Sitting in my living room lately, with its wall of books, I've been fantasizing about empty space. The advantage of books on the shelf is the visual sweep--there's a randomness factor: running your thumb along the spines you might choose to read a book you didn't intend to at first. There's a similar loss in the exchange (years ago accomplished) of digital music for CDs, but that loss is compensated somewhat by software "shuffle" features. Browsing is also still possible in digital book collections; it just becomes a conscious choice rather than a default activity. Web services like Library Thing can display book collections in multiple formats.
Slogans against digital books point out "books don't need batteries" but the physical space required by books is not trivial (says one who has lined the walls of two rooms with them). And this far-from-trivial space has very limited value beyond what it contains. It does provide a kind of eccentric eye candy and a visual reminder of what one has read and has yet to read. For the most part, though, the books are bound and printed cheaply, not made to last, and the spines fade on the shelf. The loyalty to what one has read and what one wants (or wanted at one time) to have read...sometimes it seems silly.
So find myself wishing that much of my library were digitized. As I read Wolf Hall on my Kindle last week, I had absolutely no nostalgia for turning paper pages, or lugging around a big fat tome. I was enthralled by the novel, and didn't need yellowing paper to enhance that enchantment.
It's quite impossible to contemplate buying digital copies of all my books. It would cost something around $30K (assuming ,$9.99 a book for 3,000 books). Of course, some I wouldn't want digitized, and some are not available.
It turns out that there are devices to transform real books to e-book files, and I even found a service. The devices are either really expensive or require you to turn the pages (and sometimes both)--imagine doing this for 3,000 books! Ugh. The service might be worthwhile, at least for some books not available on Kindle (they won't do a Kindle conversion for books already commercially available on ereaders, though you could get PDFs).
For now I am lightly thinning the shelves by replacing hard copies with digital versions of free or cheaply available classics by the likes of Dickens and Wharton. I have established a moratorium on buying new paper books unless they are unavailable for Kindle, or they really are better in paper (cookbooks are another example).
My library's digital conversion will happen in fits and starts, and will not be complete, but it is happening.