There's analysis across the press and the web, including from Stephen Foley in The Independent.
"What characterises Google is its very aggressive approach to copyright law," said Lee Bromberg, a partner at the Boston-based law firm Bromberg & Sunstein. "My own view, as someone who often defends intellectual property, is that in every area where Google has pushed it has been over the line, but it has an interesting carrot-and-stick approach.
"The carrot is your content gets to be displayed to Google's vast army of users, which increases rather than diminishes its commercial value to you. The stick is that it says it is just going to access your content as part of the plan to control and organise our knowledge, and that it is up to you to opt out. Well, you can't burden the copyright holder with an obligation to demand their content is not used."