You can download the new version here:
http://www.amazon.com/gp/help/custom...deId=200317150
Here are the differences between 2nd Edition and 3rd Edition:
Page 11: You can also choose to turn on the experimental application, Text-to-Speech, which will read aloud your books, newspapers, blogs, and personal documents. ---->> You can also choose to turn on the experimental application, Text-to-Speech, which will read aloud your books (where allowed by the rights holder), newspapers, blogs, and personal documents
Page 43: Whispersync is on by default to ensure a seamless reading experience for a book read across multiple Kindle devices ---->> Whispersync is on by default to ensure a seamless reading experience for a book read across multiple Kindles.
Page 52: Your Kindle can read aloud your books, newspapers, blogs, and personal documents with the Kindle Experimental application, Text-to-Speech. ---->> Your Kindle can read aloud your books (where allowed by the rights holder), newspapers, blogs, and personal documents with the Kindle Experimental application, Text-to-Speech.
Page 52: (New text) Note that if a rights holder of a book does not allow Text-to-Speech to read aloud their content, then Text-to-Speech will be grayed out in the menu and you will not be able to select it.