Amazon is Launching Library Lending for Kindle Books.
It looks like this feature will be available later this year. Amazon is working with 11,000 libraries in the U.S. to make ebooks available on any ereader device.
I couldn't find any mention of pricing so far. Maybe this will be a free feature since Kindle had made it possible for advertisers to bring you boring adds while you are reading. Glad I have a Kindle 2, no adds.