IANAL (I am not a lawyer), but IAAL (I am a Librarian). While I personally agree that there *should* be the ability to digitize these collections and make them searchable, I think Google's in a whole heck of a mess here.
I don't think that this is necessarily fair use. The article linked to in post presents a case which relates to images, and traditionally copyright around images has been dealt with much differently than copyright related to texts, so I'm not sure how relevant the stated case might be. That being said, the one major flaw I see is that the libraries Google is partnering with purchased the books, and Google is 'borrowing' those books. If I borrow a book from my library, I am not allowed to photocopy the entire book. Maybe the Library has the right to do so for preservation (i.e. backup) or other purposes, but I do not. Even though Google is trying to hold to fair use practices through what it offers to its users, Google itself seems like it is likely to be breaking copyright by holding full copies of these works.
Now, should the publishers be making a big fuss? Well, maybe and maybe not. It doesn't appear that Google's effort will harm publishers, and is likely to help them. However, Google is not the only player out there who would be interested in massively copying monographs, and if the publishers let this pass, it might set a precedent which could come back to bite them. It isn't clear to me that the publishers are in the right, or that Google is entirely in the wrong, but if I were a publisher, I'd do the same thing, most likely.
I believe the other crux of the problem is that Google bulldozed its way forward with this project. Imagine if it was Microsoft instead of Google doing this; the slashdot comments would probably be entirely different. I admire Google moxie in pushing this issue, but I also am pained that they lacked the patience to work out some of the issues with the publishers before they pushed forward.