Libraries have been providing access to e-books for more than a decade now, but until the advent of the Kindle the model has largely been browser or at least online, web accessible e-books. You had to be tethered to the network to use the book.
The mental model users had of e-books changed in 2007 with Amazon's release of the Kindle. Now with multiple readers available readers are demanding not only online access but also the ability to download titles to their reader (or other mobile device) of choice.
Vendors for the academic market like EBSCO and ebrary are responding, if a little later than trade publishers and services like Overdrive for public libraries. So ebrary wanted to know form librarians what users were asking for in terms of downloadable ebooks.
We suggested being able to download to a wide variety of devices, making sure search, navigation, and annotation etc. features were all available and avoiding the 'check out' model, which just annoys digital users. Instead think about non-linear limits upon use (like EBL's 325 uses) whether they happen simultaneously or over time.
We should see some early versions this summer. there are lots of technical and intellectual property issues to deal with.