I've only very briefly given my thoughts on this subject, because other people have covered it in more depth and more thoughtfully than I can -- but I think it's going to become increasingly important for libraries to be able to offer digital content to their patrons, because patrons are going to increasingly demand it. I know that when I was working the desk, I got asked the "when will I be able to borrow in my Kindle?" question quite a bit. And I'm not sure that publishers won't be shooting themselves in the foot with the limited check-outs thing, either -- if libraries have options between books from a publisher that offers unlimited copies and publishers that don't, aside from the "must have" titles, they'll probably go with what their budget can afford. To me, that'd mean more permanent copies and fewer limited ones, because it ends up being a better value for the money.

But as Jeff says above, this is all in its infancy yet -- we'll have to wait and see how it all pans out!