Yeah, but isn't Google already gathering "Universal Library" content? Google Books has an astonishing number of books, and many in the public domain (though, alas!, not all) are available for PDF downloading. They've also done some auto OCRing (no checking, though, as far as I could tell) so that ascii text is availabe to view (but not download).
So the elements seem to already be in place. Rather than a subscription service, I'd love to be able to buy a particular still-in-copyright book to download instead of being redirected to Amazon or some place similar.
Maybe a subscription-with-rental service would work for research/reference books. If I'm doing a research project, I could "rent" the text of the book for, say, six months, then have the rights to view it end after the specific rental time. I say rent instead of buy because so many research/reference books are priced astronomically high.