Slightly crazy position for the authors to take - I don't fully understand the position they are taking.
From my experience, having seen one or two results popping up from Google Print, Google doesn't allow you to read the whole book. In fact, it doesn't allow you to read more than three or four pages.
What's the point of going off like this? I strongly suspect Google will \ already has put in links to Amazon or eBay so that you can buy a book immediately after reading the pages.
Once eBooks come of age (which is growing more and more likely with the rise of PSPs, better screens on mobiles and Video iPods) we would be able to buy the book immediately and receive it immediately.
If any author supports the idea of their work appearing in a public library I see no need to object to their work appearing in this. The fact that almost any book can be read for free merely by paying a visit to any of the 4,624 libraries in the UK yet book buying still remains popular is a strong indicator that demand for reading material is unlikely to be dampened by Google.