I'm a serious Kindle user -- I have dozens of books. I've thought about using DRM-cracking software to free up my books, not because of any desire to share or lend but just because it's not right having a book in my possession locked away under a secret key some other bunch of people control.
This announcement doesn't bode well for Amazon. Technology can help you find markets, technology can enable markets, but using technology to force a market to appear where none did before doesn't have such a great track record. Everybody understands that you read a book, you share it (or give it away). There is no further sale. Lendle was simply trying to help Amazon work in a natural way that people commonly understand.