Article from the NY Times
Some of the largest book publishers in the world are stripping away the anticopying software on digital downloads of audio books.
The trend will allow consumers who download audio books to freely transfer these digital files between devices like their computers, iPods and cellphones -- and conceivably share them with others. Dropping copying restrictions could also allow a variety of online retailers to start to sell audio book downloads.
With publishers like RH and Penguin releasing non-DRM audio books, one can only hope that publishers and authors might extend this to ebooks as well. I really think the tide is turning on DRM. However, I do think DRM is still good for any type of subscription/rental model.